From ben at well-typed.com  Sun Oct  1 11:17:55 2017
From: ben at well-typed.com (Ben Gamari)
Date: Sun, 01 Oct 2017 07:17:55 -0400
Subject: [ANNOUNCE] GHC 8.2.2 release candidate 1
References: <87lgr8zztf.fsf@ben-laptop.smart-cactus.org>
Message-ID: <8760bzruak.fsf@ben-laptop.smart-cactus.org>


Hello everyone,

The GHC team is very pleased to announce the first candidate of the
8.2.2 release of the Glasgow Haskell Compiler. Source and binary
distributions are available at

    https://downloads.haskell.org/~ghc/8.2.2-rc1/

Currently there is a slightly reduced set of binary distributions
available; do let me know if there is a missing platform you would like
to see built.

This is the first of two release candidates leading up the final 8.2.2
release. This release fixes approximately fifty bugs present in 8.2.1.
See [1] for the full list.

As always, please report any issues you encounter.

Happy testing,

- Ben


[1] https://ghc.haskell.org/trac/ghc/query?status=closed&milestone=8.2.2&col=id&col=summary&col=status&col=type&col=priority&col=milestone&col=component&order=priority
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From george.colpitts at gmail.com  Sun Oct  1 15:50:17 2017
From: george.colpitts at gmail.com (George Colpitts)
Date: Sun, 01 Oct 2017 15:50:17 +0000
Subject: [ANNOUNCE] GHC 8.2.2 release candidate 1
In-Reply-To: <8760bzruak.fsf@ben-laptop.smart-cactus.org>
References: <87lgr8zztf.fsf@ben-laptop.smart-cactus.org>
 <8760bzruak.fsf@ben-laptop.smart-cactus.org>
Message-ID: <CAB-d4A46HtU2zqsma1v-yT42sWdPYKytX8JF=vMfk_6dE4tCvA@mail.gmail.com>

installed fine on mac os 10.12.6 with Xcode 9.

I then installed vector, hlint, criterion and threadscope and did a smoke
test of hlint

On Sun, Oct 1, 2017 at 8:18 AM Ben Gamari <ben at well-typed.com> wrote:

>
> Hello everyone,
>
> The GHC team is very pleased to announce the first candidate of the
> 8.2.2 release of the Glasgow Haskell Compiler. Source and binary
> distributions are available at
>
>     https://downloads.haskell.org/~ghc/8.2.2-rc1/
>
> Currently there is a slightly reduced set of binary distributions
> available; do let me know if there is a missing platform you would like
> to see built.
>
> This is the first of two release candidates leading up the final 8.2.2
> release. This release fixes approximately fifty bugs present in 8.2.1.
> See [1] for the full list.
>
> As always, please report any issues you encounter.
>
> Happy testing,
>
> - Ben
>
>
> [1]
> https://ghc.haskell.org/trac/ghc/query?status=closed&milestone=8.2.2&col=id&col=summary&col=status&col=type&col=priority&col=milestone&col=component&order=priority
> _______________________________________________
> Glasgow-haskell-users mailing list
> Glasgow-haskell-users at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>
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From conal at conal.net  Mon Oct  2 21:25:59 2017
From: conal at conal.net (Conal Elliott)
Date: Mon, 2 Oct 2017 14:25:59 -0700
Subject: GHC rewrite rule type-checking failure
Message-ID: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>

I'm running into type checking problem with GHC rewrite rules in GHC 8.0.2,
illustrated in the code below. The first rule type-checks, but the second
triggers the type error mentioned in the comment following the rule
definition. I'd expect both rules to type-check, adding the needed
constraints to the applicability condition for the rule.

Is GHC's behavior intended (and perhaps necessary), or a bug?

Thanks,  -- Conal

Code (also attached):


{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}

{-# OPTIONS_GHC -Wall #-}

-- Demonstrate a type checking failure with rewrite rules

module RuleFail where

class C k where comp' :: k b c -> k a b -> k a c

instance C (->) where comp' = (.)

-- Late-inlining version to enable rewriting.
comp :: C k => k b c -> k a b -> k a c
comp = comp'
{-# INLINE [0] comp #-}

morph :: (a -> b) -> k a b
morph = error "morph: undefined"

{-# RULES "morph/(.)" morph comp = comp #-}  -- Fine

class D k a where addC' :: k (a,a) a

instance Num a => D (->) a where addC' = uncurry (+)

-- Late-inlining version to enable rewriting.
addC :: D k a => k (a,a) a
addC = addC'
{-# INLINE [0] addC #-}

{-# RULES "morph/addC" morph addC = addC #-}  -- Fail

-- • Could not deduce (D k b) arising from a use of ‘addC’
--   from the context: D (->) b

-- Why does GHC infer the (C k) constraint for the first rule but not (D k
b)
-- for the second rule?
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From mail at joachim-breitner.de  Mon Oct  2 22:52:09 2017
From: mail at joachim-breitner.de (Joachim Breitner)
Date: Mon, 02 Oct 2017 18:52:09 -0400
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
Message-ID: <1506984729.1122.11.camel@joachim-breitner.de>

Hi Conal,

The difference is that the LHS of the first rule is mentions the `C k`
constraint (probably unintentionally):

*RuleFail> :t morph comp
morph comp :: C k => k1 (k b c) (k a b -> k a c)

but the LHS of the second rule side does not:

*RuleFail> :t morph addC
morph addC :: Num b => k (b, b) b



A work-around is to add the constraint to `morph`:

    morph :: D k b => (a -> b) -> k a b
    morph = error "morph: undefined"

    but I fear that this work-around is not acceptable to you.

    Joachim

    Am Montag, den 02.10.2017, 14:25 -0700 schrieb Conal Elliott:
    > -- Demonstrate a type checking failure with rewrite rules
> 
> module RuleFail where
> 
> class C k where comp' :: k b c -> k a b -> k a c
> 
> instance C (->) where comp' = (.)
> 
> -- Late-inlining version to enable rewriting.
> comp :: C k => k b c -> k a b -> k a c
> comp = comp'
> {-# INLINE [0] comp #-}
> 
> morph :: (a -> b) -> k a b
> morph = error "morph: undefined"
> 
> {-# RULES "morph/(.)" morph comp = comp #-}  -- Fine



> class D k a where addC' :: k (a,a) a
> 
> instance Num a => D (->) a where addC' = uncurry (+)
> 
> -- Late-inlining version to enable rewriting.
> addC :: D k a => k (a,a) a
> addC = addC'
> {-# INLINE [0] addC #-}
> 
> {-# RULES "morph/addC" morph addC = addC #-}  -- Fail
> 
> -- • Could not deduce (D k b) arising from a use of ‘addC’
> --   from the context: D (->) b
> 
> -- Why does GHC infer the (C k) constraint for the first rule but not (D k b)
> -- for the second rule?
> 
> _______________________________________________
> Glasgow-haskell-users mailing list
> Glasgow-haskell-users at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
-- 
Joachim Breitner
  mail at joachim-breitner.de
  http://www.joachim-breitner.de/
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From conal at conal.net  Tue Oct  3 00:03:20 2017
From: conal at conal.net (Conal Elliott)
Date: Mon, 2 Oct 2017 17:03:20 -0700
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <1506984729.1122.11.camel@joachim-breitner.de>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
Message-ID: <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>

Thanks very much for the reply, Joachim.

Oops! I flubbed the example. I really `morph` to distribute over an
application of `comp`. New code below (and attached). You're right that I
wouldn't want to restrict the type of `morph`, since each `morph` *rule*
imposes its own restrictions.

My questions:

*   Is it feasible for GHC to combine the constraints needed LHS and RHS to
form an applicability condition?
*   Is there any way I can make the needed constraints explicit in my
rewrite rules?
*   Are there any other work-arounds that would enable writing such
RHS-constrained rules?

Regards, -- Conal

``` haskell
{-# OPTIONS_GHC -Wall #-}
-- Demonstrate a type checking failure with rewrite rules

module RuleFail where

class C k where comp' :: k b c -> k a b -> k a c

instance C (->) where comp' = (.)

-- Late-inlining version to enable rewriting.
comp :: C k => k b c -> k a b -> k a c
comp = comp'
{-# INLINE [0] comp #-}

morph :: (a -> b) -> k a b
morph = error "morph: undefined"

{-# RULES "morph/(.)" forall f g. morph (g `comp` f) = morph g `comp` morph
f #-}

-- • Could not deduce (C k) arising from a use of ‘comp’
--   from the context: C (->)
--     bound by the RULE "morph/(.)"
```


On Mon, Oct 2, 2017 at 3:52 PM, Joachim Breitner <mail at joachim-breitner.de>
wrote:

> Hi Conal,
>
> The difference is that the LHS of the first rule is mentions the `C k`
> constraint (probably unintentionally):
>
> *RuleFail> :t morph comp
> morph comp :: C k => k1 (k b c) (k a b -> k a c)
>
> but the LHS of the second rule side does not:
>
> *RuleFail> :t morph addC
> morph addC :: Num b => k (b, b) b
>
>
>
> A work-around is to add the constraint to `morph`:
>
>     morph :: D k b => (a -> b) -> k a b
>     morph = error "morph: undefined"
>
>     but I fear that this work-around is not acceptable to you.
>
>     Joachim
>
>     Am Montag, den 02.10.2017, 14:25 -0700 schrieb Conal Elliott:
>     > -- Demonstrate a type checking failure with rewrite rules
> >
> > module RuleFail where
> >
> > class C k where comp' :: k b c -> k a b -> k a c
> >
> > instance C (->) where comp' = (.)
> >
> > -- Late-inlining version to enable rewriting.
> > comp :: C k => k b c -> k a b -> k a c
> > comp = comp'
> > {-# INLINE [0] comp #-}
> >
> > morph :: (a -> b) -> k a b
> > morph = error "morph: undefined"
> >
> > {-# RULES "morph/(.)" morph comp = comp #-}  -- Fine
>
>
>
> > class D k a where addC' :: k (a,a) a
> >
> > instance Num a => D (->) a where addC' = uncurry (+)
> >
> > -- Late-inlining version to enable rewriting.
> > addC :: D k a => k (a,a) a
> > addC = addC'
> > {-# INLINE [0] addC #-}
> >
> > {-# RULES "morph/addC" morph addC = addC #-}  -- Fail
> >
> > -- • Could not deduce (D k b) arising from a use of ‘addC’
> > --   from the context: D (->) b
> >
> > -- Why does GHC infer the (C k) constraint for the first rule but not (D
> k b)
> > -- for the second rule?
> >
> > _______________________________________________
> > Glasgow-haskell-users mailing list
> > Glasgow-haskell-users at haskell.org
> > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
> --
> Joachim Breitner
>   mail at joachim-breitner.de
>   http://www.joachim-breitner.de/
>
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From david.feuer at gmail.com  Tue Oct  3 00:33:41 2017
From: david.feuer at gmail.com (David Feuer)
Date: Mon, 2 Oct 2017 20:33:41 -0400
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
 <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
Message-ID: <CAMgWh9ujTtSawnm_2jZOWURT2VA6ULOFbsJi4x5TyteLvV3sfg@mail.gmail.com>

I believe the answer is currently no. As I understand it, the entire
instance resolution mechanism drops away after type checking and is
therefore not available to the simplifier. So if you need to add a
constraint on the RHS of a rule, I think you're mostly out of luck. The
only thing I can think of is that you can look at what the specializer does
and try to look around to find the right dictionary, but that sounds hard
and brittle. OTOH, I'm not an expert, so maybe there's something major I've
missed.

On Oct 2, 2017 8:04 PM, "Conal Elliott" <conal at conal.net> wrote:

> Thanks very much for the reply, Joachim.
>
> Oops! I flubbed the example. I really `morph` to distribute over an
> application of `comp`. New code below (and attached). You're right that I
> wouldn't want to restrict the type of `morph`, since each `morph` *rule*
> imposes its own restrictions.
>
> My questions:
>
> *   Is it feasible for GHC to combine the constraints needed LHS and RHS
> to form an applicability condition?
> *   Is there any way I can make the needed constraints explicit in my
> rewrite rules?
> *   Are there any other work-arounds that would enable writing such
> RHS-constrained rules?
>
> Regards, -- Conal
>
> ``` haskell
> {-# OPTIONS_GHC -Wall #-}
> -- Demonstrate a type checking failure with rewrite rules
>
> module RuleFail where
>
> class C k where comp' :: k b c -> k a b -> k a c
>
> instance C (->) where comp' = (.)
>
> -- Late-inlining version to enable rewriting.
> comp :: C k => k b c -> k a b -> k a c
> comp = comp'
> {-# INLINE [0] comp #-}
>
> morph :: (a -> b) -> k a b
> morph = error "morph: undefined"
>
> {-# RULES "morph/(.)" forall f g. morph (g `comp` f) = morph g `comp`
> morph f #-}
>
> -- • Could not deduce (C k) arising from a use of ‘comp’
> --   from the context: C (->)
> --     bound by the RULE "morph/(.)"
> ```
>
>
> On Mon, Oct 2, 2017 at 3:52 PM, Joachim Breitner <mail at joachim-breitner.de
> > wrote:
>
>> Hi Conal,
>>
>> The difference is that the LHS of the first rule is mentions the `C k`
>> constraint (probably unintentionally):
>>
>> *RuleFail> :t morph comp
>> morph comp :: C k => k1 (k b c) (k a b -> k a c)
>>
>> but the LHS of the second rule side does not:
>>
>> *RuleFail> :t morph addC
>> morph addC :: Num b => k (b, b) b
>>
>>
>>
>> A work-around is to add the constraint to `morph`:
>>
>>     morph :: D k b => (a -> b) -> k a b
>>     morph = error "morph: undefined"
>>
>>     but I fear that this work-around is not acceptable to you.
>>
>>     Joachim
>>
>>     Am Montag, den 02.10.2017, 14:25 -0700 schrieb Conal Elliott:
>>     > -- Demonstrate a type checking failure with rewrite rules
>> >
>> > module RuleFail where
>> >
>> > class C k where comp' :: k b c -> k a b -> k a c
>> >
>> > instance C (->) where comp' = (.)
>> >
>> > -- Late-inlining version to enable rewriting.
>> > comp :: C k => k b c -> k a b -> k a c
>> > comp = comp'
>> > {-# INLINE [0] comp #-}
>> >
>> > morph :: (a -> b) -> k a b
>> > morph = error "morph: undefined"
>> >
>> > {-# RULES "morph/(.)" morph comp = comp #-}  -- Fine
>>
>>
>>
>> > class D k a where addC' :: k (a,a) a
>> >
>> > instance Num a => D (->) a where addC' = uncurry (+)
>> >
>> > -- Late-inlining version to enable rewriting.
>> > addC :: D k a => k (a,a) a
>> > addC = addC'
>> > {-# INLINE [0] addC #-}
>> >
>> > {-# RULES "morph/addC" morph addC = addC #-}  -- Fail
>> >
>> > -- • Could not deduce (D k b) arising from a use of ‘addC’
>> > --   from the context: D (->) b
>> >
>> > -- Why does GHC infer the (C k) constraint for the first rule but not
>> (D k b)
>> > -- for the second rule?
>> >
>> > _______________________________________________
>> > Glasgow-haskell-users mailing list
>> > Glasgow-haskell-users at haskell.org
>> > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>> --
>> Joachim Breitner
>>   mail at joachim-breitner.de
>>   http://www.joachim-breitner.de/
>>
>
>
> _______________________________________________
> Glasgow-haskell-users mailing list
> Glasgow-haskell-users at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>
>
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From simonpj at microsoft.com  Tue Oct  3 07:27:16 2017
From: simonpj at microsoft.com (Simon Peyton Jones)
Date: Tue, 3 Oct 2017 07:27:16 +0000
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
 <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
Message-ID: <AM4PR83MB0033AA97DAEE401F72650ADDAD720@AM4PR83MB0033.EURPRD83.prod.outlook.com>

*   Is it feasible for GHC to combine the constraints needed LHS and RHS to form an applicability condition?
I don’t think so.

Remember that a rewrite rule literally rewrites LHS to RHS.  It does not conjure up any new dictionaries out of thin air.  In your example, (D k b) is needed in the result of the rewrite.  Where can it come from?  Only from something matched on the left.

So GHC treats any dictionaries matched on the left as “givens” and tries to solve the ones matched on the left.  If it fails you get the sort of error you see.

One way to see this is to write out the rewrite rule you want, complete with all its dictionary arguments. Can you do that?

Simon

From: Glasgow-haskell-users [mailto:glasgow-haskell-users-bounces at haskell.org] On Behalf Of Conal Elliott
Sent: 03 October 2017 01:03
To: Joachim Breitner <mail at joachim-breitner.de>
Cc: glasgow-haskell-users at haskell.org
Subject: Re: GHC rewrite rule type-checking failure

Thanks very much for the reply, Joachim.

Oops! I flubbed the example. I really `morph` to distribute over an application of `comp`. New code below (and attached). You're right that I wouldn't want to restrict the type of `morph`, since each `morph` *rule* imposes its own restrictions.

My questions:

*   Is it feasible for GHC to combine the constraints needed LHS and RHS to form an applicability condition?
*   Is there any way I can make the needed constraints explicit in my rewrite rules?
*   Are there any other work-arounds that would enable writing such RHS-constrained rules?

Regards, -- Conal

``` haskell
{-# OPTIONS_GHC -Wall #-}
-- Demonstrate a type checking failure with rewrite rules

module RuleFail where

class C k where comp' :: k b c -> k a b -> k a c

instance C (->) where comp' = (.)

-- Late-inlining version to enable rewriting.
comp :: C k => k b c -> k a b -> k a c
comp = comp'
{-# INLINE [0] comp #-}

morph :: (a -> b) -> k a b
morph = error "morph: undefined"

{-# RULES "morph/(.)" forall f g. morph (g `comp` f) = morph g `comp` morph f #-}

-- • Could not deduce (C k) arising from a use of ‘comp’
--   from the context: C (->)
--     bound by the RULE "morph/(.)"
```


On Mon, Oct 2, 2017 at 3:52 PM, Joachim Breitner <mail at joachim-breitner.de<mailto:mail at joachim-breitner.de>> wrote:
Hi Conal,

The difference is that the LHS of the first rule is mentions the `C k`
constraint (probably unintentionally):

*RuleFail> :t morph comp
morph comp :: C k => k1 (k b c) (k a b -> k a c)

but the LHS of the second rule side does not:

*RuleFail> :t morph addC
morph addC :: Num b => k (b, b) b



A work-around is to add the constraint to `morph`:

    morph :: D k b => (a -> b) -> k a b
    morph = error "morph: undefined"

    but I fear that this work-around is not acceptable to you.

    Joachim

    Am Montag, den 02.10.2017, 14:25 -0700 schrieb Conal Elliott:
    > -- Demonstrate a type checking failure with rewrite rules
>
> module RuleFail where
>
> class C k where comp' :: k b c -> k a b -> k a c
>
> instance C (->) where comp' = (.)
>
> -- Late-inlining version to enable rewriting.
> comp :: C k => k b c -> k a b -> k a c
> comp = comp'
> {-# INLINE [0] comp #-}
>
> morph :: (a -> b) -> k a b
> morph = error "morph: undefined"
>
> {-# RULES "morph/(.)" morph comp = comp #-}  -- Fine



> class D k a where addC' :: k (a,a) a
>
> instance Num a => D (->) a where addC' = uncurry (+)
>
> -- Late-inlining version to enable rewriting.
> addC :: D k a => k (a,a) a
> addC = addC'
> {-# INLINE [0] addC #-}
>
> {-# RULES "morph/addC" morph addC = addC #-}  -- Fail
>
> -- • Could not deduce (D k b) arising from a use of ‘addC’
> --   from the context: D (->) b
>
> -- Why does GHC infer the (C k) constraint for the first rule but not (D k b)
> -- for the second rule?
>
> _______________________________________________
> Glasgow-haskell-users mailing list
> Glasgow-haskell-users at haskell.org<mailto:Glasgow-haskell-users at haskell.org>
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmail.haskell.org%2Fcgi-bin%2Fmailman%2Flistinfo%2Fglasgow-haskell-users&data=02%7C01%7Csimonpj%40microsoft.com%7C3da5c75572694bab31aa08d509f25936%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636425858847457302&sdata=6dcqjyAYmKXKwZzQQExmWl1cJlCySmP1EvdjA03O19M%3D&reserved=0>
--
Joachim Breitner
  mail at joachim-breitner.de<mailto:mail at joachim-breitner.de>
  http://www.joachim-breitner.de/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.joachim-breitner.de%2F&data=02%7C01%7Csimonpj%40microsoft.com%7C3da5c75572694bab31aa08d509f25936%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636425858847457302&sdata=Uoe%2Bw8T3VMFLRsFY%2B8nacXIV0pUQOyCe4iHz%2FS5kGrA%3D&reserved=0>

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From takenobu.hs at gmail.com  Tue Oct  3 12:07:33 2017
From: takenobu.hs at gmail.com (Takenobu Tani)
Date: Tue, 3 Oct 2017 21:07:33 +0900
Subject: [ANNOUNCE] GHC 8.2.2 release candidate 1
In-Reply-To: <8760bzruak.fsf@ben-laptop.smart-cactus.org>
References: <87lgr8zztf.fsf@ben-laptop.smart-cactus.org>
 <8760bzruak.fsf@ben-laptop.smart-cactus.org>
Message-ID: <CAPB_NvwzH=mUnwc9=63Th25T7mPX6B534erfUeY2upct5EJeEA@mail.gmail.com>

Hi Ben, devs,

Thanks for your hard work!

Could you also include the following commits?
These are about user's guide.

  * https://phabricator.haskell.org/D3850
  * https://phabricator.haskell.org/D3852

Regards,
Takenobu



2017-10-01 20:17 GMT+09:00 Ben Gamari <ben at well-typed.com>:

>
> Hello everyone,
>
> The GHC team is very pleased to announce the first candidate of the
> 8.2.2 release of the Glasgow Haskell Compiler. Source and binary
> distributions are available at
>
>     https://downloads.haskell.org/~ghc/8.2.2-rc1/
>
> Currently there is a slightly reduced set of binary distributions
> available; do let me know if there is a missing platform you would like
> to see built.
>
> This is the first of two release candidates leading up the final 8.2.2
> release. This release fixes approximately fifty bugs present in 8.2.1.
> See [1] for the full list.
>
> As always, please report any issues you encounter.
>
> Happy testing,
>
> - Ben
>
>
> [1] https://ghc.haskell.org/trac/ghc/query?status=closed&
> milestone=8.2.2&col=id&col=summary&col=status&col=type&
> col=priority&col=milestone&col=component&order=priority
>
> _______________________________________________
> Glasgow-haskell-users mailing list
> Glasgow-haskell-users at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>
>
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From ben at well-typed.com  Tue Oct  3 14:47:50 2017
From: ben at well-typed.com (Ben Gamari)
Date: Tue, 03 Oct 2017 10:47:50 -0400
Subject: [ANNOUNCE] GHC 8.2.2 release candidate 1
In-Reply-To: <CAPB_NvwzH=mUnwc9=63Th25T7mPX6B534erfUeY2upct5EJeEA@mail.gmail.com>
References: <87lgr8zztf.fsf@ben-laptop.smart-cactus.org>
 <8760bzruak.fsf@ben-laptop.smart-cactus.org>
 <CAPB_NvwzH=mUnwc9=63Th25T7mPX6B534erfUeY2upct5EJeEA@mail.gmail.com>
Message-ID: <871smkqodl.fsf@ben-laptop.smart-cactus.org>

Takenobu Tani <takenobu.hs at gmail.com> writes:

> Hi Ben, devs,
>
> Thanks for your hard work!
>
> Could you also include the following commits?
> These are about user's guide.
>
>   * https://phabricator.haskell.org/D3850
>   * https://phabricator.haskell.org/D3852
>
Of course, thanks!

Cheers,

- Ben
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From mail at joachim-breitner.de  Tue Oct  3 14:52:07 2017
From: mail at joachim-breitner.de (Joachim Breitner)
Date: Tue, 03 Oct 2017 10:52:07 -0400
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
 <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
Message-ID: <1507042327.15155.5.camel@joachim-breitner.de>

Hi,


Am Montag, den 02.10.2017, 17:03 -0700 schrieb Conal Elliott:
> My questions:
> 
> *   Is it feasible for GHC to combine the constraints needed LHS and RHS to form an applicability condition?
> *   Is there any way I can make the needed constraints explicit in my rewrite rules?
> *   Are there any other work-arounds that would enable writing such RHS-constrained rules?

if you are fine writing one RULE per _instance_ of C, the following
works:


    {-# LANGUAGE ExplicitForAll, TypeApplications #-}
    {-# OPTIONS_GHC -Wall #-}
    module RuleFail where
    class C k where comp' :: k b c -> k a b -> k a c

    instance C (->) where comp' = (.)
    instance C (,) where comp' (_,a) (c,_) = (c,a)

    -- Late-inlining version to enable rewriting.
    comp :: C k => k b c -> k a b -> k a c
    comp = comp'
    {-# INLINE [0] comp #-}

    morph :: forall k a b. (a -> b) -> k a b
    morph _ = error "morph: undefined"
    {-# NOINLINE morph #-}

    {-# RULES "morph/(.)/->"  forall f g. morph @(->) (g `comp` f) = morph g `comp` morph f #-}
    {-# RULES "morph/(.)/(,)" forall f g. morph @(,) (g `comp` f) =
    morph g `comp` morph f #-}


Let’s look at the rules:

    $ ghc -O -c -ddump-rules RuleFail.hs 

    ==================== Tidy Core rules ====================
    "morph/(.)/(,)" [ALWAYS]
        forall (@ b)
               (@ b1)
               (@ a)
               ($dC :: C (->))
               (f :: a -> b)
               (g :: b -> b1).
          morph @ (,) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
          = comp
              @ (,)
              @ b
              @ b1
              @ a
              $fC(,)
              (morph @ (,) @ b @ b1 g)
              (morph @ (,) @ a @ b f)
    "morph/(.)/->" [ALWAYS]
        forall (@ b)
               (@ b1)
               (@ a)
               ($dC :: C (->))
               (f :: a -> b)
               (g :: b -> b1).
          morph @ (->) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
          = comp
              @ (->)
              @ b
              @ b1
              @ a
              $dC
              (morph @ (->) @ b @ b1 g)
              (morph @ (->) @ a @ b f)

    As you can see, by specializing the rule to a specific k, GHC can
    include the concrete instance dictionary (here, $fC(,)) _in the rule_
    so it does not have to appear on the LHS. This is pretty much how
    specialization works.

    Is that a viable work-around for you? It involves boilerplate code, but
    nothing that cannot be explained in the documentation. (Or maybe TH can
    create such rules?)


    If this idiom turns out to be useful, I wonder if there is a case for
    -rules specified in type classes that get instantiated upon every
    instance, e.g.

    class C k where
        comp' :: k b c -> k a b -> k a c
        {-# RULES "morph/(.)/(,)" forall f g. morph @k (g `comp` f) = morph g `comp` morph f #-}


    Greetings,
    Joachim
    -- 
    Joachim Breitner
  mail at joachim-breitner.de
  http://www.joachim-breitner.de/
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From conal at conal.net  Tue Oct  3 15:45:45 2017
From: conal at conal.net (Conal Elliott)
Date: Tue, 3 Oct 2017 08:45:45 -0700
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <1507042327.15155.5.camel@joachim-breitner.de>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
 <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
 <1507042327.15155.5.camel@joachim-breitner.de>
Message-ID: <CAD6SzR+XUrRebpU0f3CGinBqSpNUNnS5ytr55JZOQ-2Hjqy21Q@mail.gmail.com>

Hi Joachim. Thanks very much for the suggestions and the `-ddump-rules`
view. I wouldn't want to make people write `morph` rules for all
combinations of operations (like `(.)`) and categories, but perhaps as you
suggest those rules can be generated automatically.

Regards, - Conal

On Tue, Oct 3, 2017 at 7:52 AM, Joachim Breitner <mail at joachim-breitner.de>
wrote:

> Hi,
>
>
> Am Montag, den 02.10.2017, 17:03 -0700 schrieb Conal Elliott:
> > My questions:
> >
> > *   Is it feasible for GHC to combine the constraints needed LHS and RHS
> to form an applicability condition?
> > *   Is there any way I can make the needed constraints explicit in my
> rewrite rules?
> > *   Are there any other work-arounds that would enable writing such
> RHS-constrained rules?
>
> if you are fine writing one RULE per _instance_ of C, the following
> works:
>
>
>     {-# LANGUAGE ExplicitForAll, TypeApplications #-}
>     {-# OPTIONS_GHC -Wall #-}
>     module RuleFail where
>     class C k where comp' :: k b c -> k a b -> k a c
>
>     instance C (->) where comp' = (.)
>     instance C (,) where comp' (_,a) (c,_) = (c,a)
>
>     -- Late-inlining version to enable rewriting.
>     comp :: C k => k b c -> k a b -> k a c
>     comp = comp'
>     {-# INLINE [0] comp #-}
>
>     morph :: forall k a b. (a -> b) -> k a b
>     morph _ = error "morph: undefined"
>     {-# NOINLINE morph #-}
>
>     {-# RULES "morph/(.)/->"  forall f g. morph @(->) (g `comp` f) = morph
> g `comp` morph f #-}
>     {-# RULES "morph/(.)/(,)" forall f g. morph @(,) (g `comp` f) =
>     morph g `comp` morph f #-}
>
>
> Let’s look at the rules:
>
>     $ ghc -O -c -ddump-rules RuleFail.hs
>
>     ==================== Tidy Core rules ====================
>     "morph/(.)/(,)" [ALWAYS]
>         forall (@ b)
>                (@ b1)
>                (@ a)
>                ($dC :: C (->))
>                (f :: a -> b)
>                (g :: b -> b1).
>           morph @ (,) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
>           = comp
>               @ (,)
>               @ b
>               @ b1
>               @ a
>               $fC(,)
>               (morph @ (,) @ b @ b1 g)
>               (morph @ (,) @ a @ b f)
>     "morph/(.)/->" [ALWAYS]
>         forall (@ b)
>                (@ b1)
>                (@ a)
>                ($dC :: C (->))
>                (f :: a -> b)
>                (g :: b -> b1).
>           morph @ (->) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
>           = comp
>               @ (->)
>               @ b
>               @ b1
>               @ a
>               $dC
>               (morph @ (->) @ b @ b1 g)
>               (morph @ (->) @ a @ b f)
>
>     As you can see, by specializing the rule to a specific k, GHC can
>     include the concrete instance dictionary (here, $fC(,)) _in the rule_
>     so it does not have to appear on the LHS. This is pretty much how
>     specialization works.
>
>     Is that a viable work-around for you? It involves boilerplate code, but
>     nothing that cannot be explained in the documentation. (Or maybe TH can
>     create such rules?)
>
>
>     If this idiom turns out to be useful, I wonder if there is a case for
>     -rules specified in type classes that get instantiated upon every
>     instance, e.g.
>
>     class C k where
>         comp' :: k b c -> k a b -> k a c
>         {-# RULES "morph/(.)/(,)" forall f g. morph @k (g `comp` f) =
> morph g `comp` morph f #-}
>
>
>     Greetings,
>     Joachim
>     --
>     Joachim Breitner
>   mail at joachim-breitner.de
>   http://www.joachim-breitner.de/
>
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From mail at joachim-breitner.de  Tue Oct  3 15:49:18 2017
From: mail at joachim-breitner.de (Joachim Breitner)
Date: Tue, 03 Oct 2017 11:49:18 -0400
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <CAD6SzR+XUrRebpU0f3CGinBqSpNUNnS5ytr55JZOQ-2Hjqy21Q@mail.gmail.com>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
 <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
 <1507042327.15155.5.camel@joachim-breitner.de>
 <CAD6SzR+XUrRebpU0f3CGinBqSpNUNnS5ytr55JZOQ-2Hjqy21Q@mail.gmail.com>
Message-ID: <1507045758.15155.7.camel@joachim-breitner.de>

Hi,

Now that I think about it: You can probably even generate these rules
in a core2core pass that looks for instances of C, and then adds the
rules to the mod_guts. That would solve the problem neatly, I’d say.

Greetings,
Joachim


Am Dienstag, den 03.10.2017, 08:45 -0700 schrieb Conal Elliott:
> Hi Joachim. Thanks very much for the suggestions and the `-ddump-
> rules` view. I wouldn't want to make people write `morph` rules for
> all combinations of operations (like `(.)`) and categories, but
> perhaps as you suggest those rules can be generated automatically.
> 
> Regards, - Conal
> 
> On Tue, Oct 3, 2017 at 7:52 AM, Joachim Breitner <mail at joachim-breitner.de> wrote:
> > Hi,
> > 
> > 
> > Am Montag, den 02.10.2017, 17:03 -0700 schrieb Conal Elliott:
> > > My questions:
> > >
> > > *   Is it feasible for GHC to combine the constraints needed LHS and RHS to form an applicability condition?
> > > *   Is there any way I can make the needed constraints explicit in my rewrite rules?
> > > *   Are there any other work-arounds that would enable writing such RHS-constrained rules?
> > 
> > if you are fine writing one RULE per _instance_ of C, the following
> > works:
> > 
> > 
> >     {-# LANGUAGE ExplicitForAll, TypeApplications #-}
> >     {-# OPTIONS_GHC -Wall #-}
> >     module RuleFail where
> >     class C k where comp' :: k b c -> k a b -> k a c
> > 
> >     instance C (->) where comp' = (.)
> >     instance C (,) where comp' (_,a) (c,_) = (c,a)
> > 
> >     -- Late-inlining version to enable rewriting.
> >     comp :: C k => k b c -> k a b -> k a c
> >     comp = comp'
> >     {-# INLINE [0] comp #-}
> > 
> >     morph :: forall k a b. (a -> b) -> k a b
> >     morph _ = error "morph: undefined"
> >     {-# NOINLINE morph #-}
> > 
> >     {-# RULES "morph/(.)/->"  forall f g. morph @(->) (g `comp` f) = morph g `comp` morph f #-}
> >     {-# RULES "morph/(.)/(,)" forall f g. morph @(,) (g `comp` f) =
> >     morph g `comp` morph f #-}
> > 
> > 
> > Let’s look at the rules:
> > 
> >     $ ghc -O -c -ddump-rules RuleFail.hs
> > 
> >     ==================== Tidy Core rules ====================
> >     "morph/(.)/(,)" [ALWAYS]
> >         forall (@ b)
> >                (@ b1)
> >                (@ a)
> >                ($dC :: C (->))
> >                (f :: a -> b)
> >                (g :: b -> b1).
> >           morph @ (,) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
> >           = comp
> >               @ (,)
> >               @ b
> >               @ b1
> >               @ a
> >               $fC(,)
> >               (morph @ (,) @ b @ b1 g)
> >               (morph @ (,) @ a @ b f)
> >     "morph/(.)/->" [ALWAYS]
> >         forall (@ b)
> >                (@ b1)
> >                (@ a)
> >                ($dC :: C (->))
> >                (f :: a -> b)
> >                (g :: b -> b1).
> >           morph @ (->) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
> >           = comp
> >               @ (->)
> >               @ b
> >               @ b1
> >               @ a
> >               $dC
> >               (morph @ (->) @ b @ b1 g)
> >               (morph @ (->) @ a @ b f)
> > 
> >     As you can see, by specializing the rule to a specific k, GHC can
> >     include the concrete instance dictionary (here, $fC(,)) _in the rule_
> >     so it does not have to appear on the LHS. This is pretty much how
> >     specialization works.
> > 
> >     Is that a viable work-around for you? It involves boilerplate code, but
> >     nothing that cannot be explained in the documentation. (Or maybe TH can
> >     create such rules?)
> > 
> > 
> >     If this idiom turns out to be useful, I wonder if there is a case for
> >     -rules specified in type classes that get instantiated upon every
> >     instance, e.g.
> > 
> >     class C k where
> >         comp' :: k b c -> k a b -> k a c
> >         {-# RULES "morph/(.)/(,)" forall f g. morph @k (g `comp` f) = morph g `comp` morph f #-}
> > 
> > 
> >     Greetings,
> >     Joachim
> >     --
> >     Joachim Breitner
> >   mail at joachim-breitner.de
> >   http://www.joachim-breitner.de/
> 
> 
-- 
Joachim Breitner
  mail at joachim-breitner.de
  http://www.joachim-breitner.de/
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From conal at conal.net  Tue Oct  3 16:01:07 2017
From: conal at conal.net (Conal Elliott)
Date: Tue, 3 Oct 2017 09:01:07 -0700
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <1507045758.15155.7.camel@joachim-breitner.de>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
 <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
 <1507042327.15155.5.camel@joachim-breitner.de>
 <CAD6SzR+XUrRebpU0f3CGinBqSpNUNnS5ytr55JZOQ-2Hjqy21Q@mail.gmail.com>
 <1507045758.15155.7.camel@joachim-breitner.de>
Message-ID: <CAD6SzRK1xWscF+Ad1m3_LAH3YPLhh40jCvrQLEWXw=abCkcOPw@mail.gmail.com>

Thanks for the suggestion, Joachim.

Since I'm writing a core-to-core plugin anyway, it wasn't so hard for me to
implement all of these n*m rules (for n operations and m instances) at once
via a "built-in" rewrite rule that explicitly manipulates Core expressions.
Doing so is probably also considerably more efficient than matching against
many rewrite rules (whether generated manually or automatically), at least
the way rewrite rule matching is currently implemented. As you & I
discussed at ICFP, I'm looking for ways to reduce the complexity of the
plugin to make it easier to maintain and extend, and I thought that
dictionary synthesis from rewrite rules might be one.

Regards,
-- Conal

On Tue, Oct 3, 2017 at 8:49 AM, Joachim Breitner <mail at joachim-breitner.de>
wrote:

> Hi,
>
> Now that I think about it: You can probably even generate these rules
> in a core2core pass that looks for instances of C, and then adds the
> rules to the mod_guts. That would solve the problem neatly, I’d say.
>
> Greetings,
> Joachim
>
>
> Am Dienstag, den 03.10.2017, 08:45 -0700 schrieb Conal Elliott:
> > Hi Joachim. Thanks very much for the suggestions and the `-ddump-
> > rules` view. I wouldn't want to make people write `morph` rules for
> > all combinations of operations (like `(.)`) and categories, but
> > perhaps as you suggest those rules can be generated automatically.
> >
> > Regards, - Conal
> >
> > On Tue, Oct 3, 2017 at 7:52 AM, Joachim Breitner <
> mail at joachim-breitner.de> wrote:
> > > Hi,
> > >
> > >
> > > Am Montag, den 02.10.2017, 17:03 -0700 schrieb Conal Elliott:
> > > > My questions:
> > > >
> > > > *   Is it feasible for GHC to combine the constraints needed LHS and
> RHS to form an applicability condition?
> > > > *   Is there any way I can make the needed constraints explicit in
> my rewrite rules?
> > > > *   Are there any other work-arounds that would enable writing such
> RHS-constrained rules?
> > >
> > > if you are fine writing one RULE per _instance_ of C, the following
> > > works:
> > >
> > >
> > >     {-# LANGUAGE ExplicitForAll, TypeApplications #-}
> > >     {-# OPTIONS_GHC -Wall #-}
> > >     module RuleFail where
> > >     class C k where comp' :: k b c -> k a b -> k a c
> > >
> > >     instance C (->) where comp' = (.)
> > >     instance C (,) where comp' (_,a) (c,_) = (c,a)
> > >
> > >     -- Late-inlining version to enable rewriting.
> > >     comp :: C k => k b c -> k a b -> k a c
> > >     comp = comp'
> > >     {-# INLINE [0] comp #-}
> > >
> > >     morph :: forall k a b. (a -> b) -> k a b
> > >     morph _ = error "morph: undefined"
> > >     {-# NOINLINE morph #-}
> > >
> > >     {-# RULES "morph/(.)/->"  forall f g. morph @(->) (g `comp` f) =
> morph g `comp` morph f #-}
> > >     {-# RULES "morph/(.)/(,)" forall f g. morph @(,) (g `comp` f) =
> > >     morph g `comp` morph f #-}
> > >
> > >
> > > Let’s look at the rules:
> > >
> > >     $ ghc -O -c -ddump-rules RuleFail.hs
> > >
> > >     ==================== Tidy Core rules ====================
> > >     "morph/(.)/(,)" [ALWAYS]
> > >         forall (@ b)
> > >                (@ b1)
> > >                (@ a)
> > >                ($dC :: C (->))
> > >                (f :: a -> b)
> > >                (g :: b -> b1).
> > >           morph @ (,) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
> > >           = comp
> > >               @ (,)
> > >               @ b
> > >               @ b1
> > >               @ a
> > >               $fC(,)
> > >               (morph @ (,) @ b @ b1 g)
> > >               (morph @ (,) @ a @ b f)
> > >     "morph/(.)/->" [ALWAYS]
> > >         forall (@ b)
> > >                (@ b1)
> > >                (@ a)
> > >                ($dC :: C (->))
> > >                (f :: a -> b)
> > >                (g :: b -> b1).
> > >           morph @ (->) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
> > >           = comp
> > >               @ (->)
> > >               @ b
> > >               @ b1
> > >               @ a
> > >               $dC
> > >               (morph @ (->) @ b @ b1 g)
> > >               (morph @ (->) @ a @ b f)
> > >
> > >     As you can see, by specializing the rule to a specific k, GHC can
> > >     include the concrete instance dictionary (here, $fC(,)) _in the
> rule_
> > >     so it does not have to appear on the LHS. This is pretty much how
> > >     specialization works.
> > >
> > >     Is that a viable work-around for you? It involves boilerplate
> code, but
> > >     nothing that cannot be explained in the documentation. (Or maybe
> TH can
> > >     create such rules?)
> > >
> > >
> > >     If this idiom turns out to be useful, I wonder if there is a case
> for
> > >     -rules specified in type classes that get instantiated upon every
> > >     instance, e.g.
> > >
> > >     class C k where
> > >         comp' :: k b c -> k a b -> k a c
> > >         {-# RULES "morph/(.)/(,)" forall f g. morph @k (g `comp` f) =
> morph g `comp` morph f #-}
> > >
> > >
> > >     Greetings,
> > >     Joachim
> > >     --
> > >     Joachim Breitner
> > >   mail at joachim-breitner.de
> > >   http://www.joachim-breitner.de/
> >
> >
> --
> Joachim Breitner
>   mail at joachim-breitner.de
>   http://www.joachim-breitner.de/
>
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From mail at joachim-breitner.de  Wed Oct  4 14:55:21 2017
From: mail at joachim-breitner.de (Joachim Breitner)
Date: Wed, 04 Oct 2017 10:55:21 -0400
Subject: GHC rewrite rule type-checking failure
In-Reply-To: <CAD6SzRK1xWscF+Ad1m3_LAH3YPLhh40jCvrQLEWXw=abCkcOPw@mail.gmail.com>
References: <CAD6SzRKj2Kz044CkbXA2FAzAY0oRMftxvb-QeAZ8o0zCSW1WNg@mail.gmail.com>
 <1506984729.1122.11.camel@joachim-breitner.de>
 <CAD6SzRLUsAqCkcXWEZde-VptDyWtQtJrCrOOwdVwvLaBL619ww@mail.gmail.com>
 <1507042327.15155.5.camel@joachim-breitner.de>
 <CAD6SzR+XUrRebpU0f3CGinBqSpNUNnS5ytr55JZOQ-2Hjqy21Q@mail.gmail.com>
 <1507045758.15155.7.camel@joachim-breitner.de>
 <CAD6SzRK1xWscF+Ad1m3_LAH3YPLhh40jCvrQLEWXw=abCkcOPw@mail.gmail.com>
Message-ID: <1507128921.968.2.camel@joachim-breitner.de>

Hi,

I think creating your rules as built-in rules is a good way to go.

You could reduce the complexity somewhat by generating all n*m rules as
“normal” rules in the plugin when you see the instancs. This way, the
plugin does not have to do anything when you want the rule to actually
file (…and maybe the plugin does not have to be loaded at all). But I
am not sure if it is worth the effort. And the built-in rules are more
efficient, as you say.

Greetings,
Joachim

Am Dienstag, den 03.10.2017, 09:01 -0700 schrieb Conal Elliott:
> Thanks for the suggestion, Joachim.
> 
> Since I'm writing a core-to-core plugin anyway, it wasn't so hard for
> me to implement all of these n*m rules (for n operations and m
> instances) at once via a "built-in" rewrite rule that explicitly
> manipulates Core expressions. Doing so is probably also considerably
> more efficient than matching against many rewrite rules (whether
> generated manually or automatically), at least the way rewrite rule
> matching is currently implemented. As you & I discussed at ICFP, I'm
> looking for ways to reduce the complexity of the plugin to make it
> easier to maintain and extend, and I thought that dictionary
> synthesis from rewrite rules might be one.
> 
> Regards,
> -- Conal
> 
> On Tue, Oct 3, 2017 at 8:49 AM, Joachim Breitner <mail at joachim-breitner.de> wrote:
> > Hi,
> > 
> > Now that I think about it: You can probably even generate these rules
> > in a core2core pass that looks for instances of C, and then adds the
> > rules to the mod_guts. That would solve the problem neatly, I’d say.
> > 
> > Greetings,
> > Joachim
> > 
> > 
> > Am Dienstag, den 03.10.2017, 08:45 -0700 schrieb Conal Elliott:
> > > Hi Joachim. Thanks very much for the suggestions and the `-ddump-
> > > rules` view. I wouldn't want to make people write `morph` rules for
> > > all combinations of operations (like `(.)`) and categories, but
> > > perhaps as you suggest those rules can be generated automatically.
> > >
> > > Regards, - Conal
> > >
> > > On Tue, Oct 3, 2017 at 7:52 AM, Joachim Breitner <mail at joachim-breitner.de> wrote:
> > > > Hi,
> > > >
> > > >
> > > > Am Montag, den 02.10.2017, 17:03 -0700 schrieb Conal Elliott:
> > > > > My questions:
> > > > >
> > > > > *   Is it feasible for GHC to combine the constraints needed LHS and RHS to form an applicability condition?
> > > > > *   Is there any way I can make the needed constraints explicit in my rewrite rules?
> > > > > *   Are there any other work-arounds that would enable writing such RHS-constrained rules?
> > > >
> > > > if you are fine writing one RULE per _instance_ of C, the following
> > > > works:
> > > >
> > > >
> > > >     {-# LANGUAGE ExplicitForAll, TypeApplications #-}
> > > >     {-# OPTIONS_GHC -Wall #-}
> > > >     module RuleFail where
> > > >     class C k where comp' :: k b c -> k a b -> k a c
> > > >
> > > >     instance C (->) where comp' = (.)
> > > >     instance C (,) where comp' (_,a) (c,_) = (c,a)
> > > >
> > > >     -- Late-inlining version to enable rewriting.
> > > >     comp :: C k => k b c -> k a b -> k a c
> > > >     comp = comp'
> > > >     {-# INLINE [0] comp #-}
> > > >
> > > >     morph :: forall k a b. (a -> b) -> k a b
> > > >     morph _ = error "morph: undefined"
> > > >     {-# NOINLINE morph #-}
> > > >
> > > >     {-# RULES "morph/(.)/->"  forall f g. morph @(->) (g `comp` f) = morph g `comp` morph f #-}
> > > >     {-# RULES "morph/(.)/(,)" forall f g. morph @(,) (g `comp` f) =
> > > >     morph g `comp` morph f #-}
> > > >
> > > >
> > > > Let’s look at the rules:
> > > >
> > > >     $ ghc -O -c -ddump-rules RuleFail.hs
> > > >
> > > >     ==================== Tidy Core rules ====================
> > > >     "morph/(.)/(,)" [ALWAYS]
> > > >         forall (@ b)
> > > >                (@ b1)
> > > >                (@ a)
> > > >                ($dC :: C (->))
> > > >                (f :: a -> b)
> > > >                (g :: b -> b1).
> > > >           morph @ (,) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
> > > >           = comp
> > > >               @ (,)
> > > >               @ b
> > > >               @ b1
> > > >               @ a
> > > >               $fC(,)
> > > >               (morph @ (,) @ b @ b1 g)
> > > >               (morph @ (,) @ a @ b f)
> > > >     "morph/(.)/->" [ALWAYS]
> > > >         forall (@ b)
> > > >                (@ b1)
> > > >                (@ a)
> > > >                ($dC :: C (->))
> > > >                (f :: a -> b)
> > > >                (g :: b -> b1).
> > > >           morph @ (->) @ a @ b1 (comp @ (->) @ b @ b1 @ a $dC g f)
> > > >           = comp
> > > >               @ (->)
> > > >               @ b
> > > >               @ b1
> > > >               @ a
> > > >               $dC
> > > >               (morph @ (->) @ b @ b1 g)
> > > >               (morph @ (->) @ a @ b f)
> > > >
> > > >     As you can see, by specializing the rule to a specific k, GHC can
> > > >     include the concrete instance dictionary (here, $fC(,)) _in the rule_
> > > >     so it does not have to appear on the LHS. This is pretty much how
> > > >     specialization works.
> > > >
> > > >     Is that a viable work-around for you? It involves boilerplate code, but
> > > >     nothing that cannot be explained in the documentation. (Or maybe TH can
> > > >     create such rules?)
> > > >
> > > >
> > > >     If this idiom turns out to be useful, I wonder if there is a case for
> > > >     -rules specified in type classes that get instantiated upon every
> > > >     instance, e.g.
> > > >
> > > >     class C k where
> > > >         comp' :: k b c -> k a b -> k a c
> > > >         {-# RULES "morph/(.)/(,)" forall f g. morph @k (g `comp` f) = morph g `comp` morph f #-}
> > > >
> > > >
> > > >     Greetings,
> > > >     Joachim
> > > >     --
> > > >     Joachim Breitner
> > > >   mail at joachim-breitner.de
> > > >   http://www.joachim-breitner.de/
> > >
> > >
> > --
> > Joachim Breitner
> >   mail at joachim-breitner.de
> >   http://www.joachim-breitner.de/
> 
> _______________________________________________
> Glasgow-haskell-users mailing list
> Glasgow-haskell-users at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
-- 
Joachim Breitner
  mail at joachim-breitner.de
  http://www.joachim-breitner.de/
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From michael.james.mcculloch at gmail.com  Fri Oct 20 14:02:31 2017
From: michael.james.mcculloch at gmail.com (Michael McCulloch)
Date: Fri, 20 Oct 2017 14:02:31 +0000
Subject: Getting segmentation fault on stack/cabal -any command, including
 stack --install-ghc, On windows.
Message-ID: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>

Hello.

After searching around I can't find people with a similar issue (Maybe I'm
looking in the wrong places?).

I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal 2.0.0.0.
Windows 10 Fall Creators Update( This issue was also occurring pre FCU).
The issue also occurs with 8.0.2a

Prior to FCU, I could run ghci directly, but now i get:

    Access violation in generated code when reading 00000000046710f6

Can anyone help me out?
-- 

Michael McCulloch

c: (403) 629-9645
e: michael.james.mcculloch at gmail.com
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From tamar at zhox.com  Fri Oct 20 22:08:16 2017
From: tamar at zhox.com (Tamar Christina)
Date: Fri, 20 Oct 2017 22:08:16 +0000
Subject: Getting segmentation fault on stack/cabal -any command,
 including stack --install-ghc, On windows.
In-Reply-To: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
Message-ID: <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>

Hi Michael,

Does this happen only with 8.2.1?

Can you try a clean vanilla GHC?
https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz

just to rule out any issues with toolings.

if it still happens, does ghci -v3 show anything?

if it still crashes can you run procdump on GHC directly and return the dump?

https://docs.microsoft.com/en-us/sysinternals/downloads/procdump

with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"

Thanks,
Tamar 


 ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ---- 
 > Hello.
 > After searching around I can't find people with a similar issue (Maybe I'm looking in the wrong places?).
 > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal 2.0.0.0. Windows 10 Fall Creators Update( This issue was also occurring pre FCU). The issue also occurs with 8.0.2a
 > Prior to FCU, I could run ghci directly, but now i get: 
 >     Access violation in generated code when reading 00000000046710f6
 > Can anyone help me out?-- 
 > Michael McCulloch
 >  c: (403) 629-9645
 >  e: michael.james.mcculloch at gmail.com 
 >   _______________________________________________
 > Glasgow-haskell-users mailing list
 > Glasgow-haskell-users at haskell.org
 > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 > 



From michael.james.mcculloch at gmail.com  Fri Oct 20 23:51:43 2017
From: michael.james.mcculloch at gmail.com (Michael McCulloch)
Date: Fri, 20 Oct 2017 23:51:43 +0000
Subject: Getting segmentation fault on stack/cabal -any command, including
 stack --install-ghc, On windows.
In-Reply-To: <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
 <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
Message-ID: <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>

Previously to FCU, the issue was also occuring with ghc8.0.2(a), however,
it would appear that it is working again.

I have provided the output of ghci -v3 *8.2.1).

I was unable to run procdump, it was giving me directory does not exist,
even when placed in the bin folder.

On Fri, Oct 20, 2017 at 4:08 PM Tamar Christina <tamar at zhox.com> wrote:

> Hi Michael,
>
> Does this happen only with 8.2.1?
>
> Can you try a clean vanilla GHC?
>
> https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz
>
> just to rule out any issues with toolings.
>
> if it still happens, does ghci -v3 show anything?
>
> if it still crashes can you run procdump on GHC directly and return the
> dump?
>
> https://docs.microsoft.com/en-us/sysinternals/downloads/procdump
>
> with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"
>
> Thanks,
> Tamar
>
>
>  ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <
> michael.james.mcculloch at gmail.com> wrote ----
>  > Hello.
>  > After searching around I can't find people with a similar issue (Maybe
> I'm looking in the wrong places?).
>  > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal 2.0.0.0.
> Windows 10 Fall Creators Update( This issue was also occurring pre FCU).
> The issue also occurs with 8.0.2a
>  > Prior to FCU, I could run ghci directly, but now i get:
>  >     Access violation in generated code when reading 00000000046710f6
>  > Can anyone help me out?--
>  > Michael McCulloch
>  >  c: (403) 629-9645
>  >  e: michael.james.mcculloch at gmail.com
>  >   _______________________________________________
>  > Glasgow-haskell-users mailing list
>  > Glasgow-haskell-users at haskell.org
>  > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>  >
>
>
> --

Michael McCulloch

c: (403) 629-9645
e: michael.james.mcculloch at gmail.com
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-------------- next part --------------
GHCi, version 8.2.1: http://www.haskell.org/ghc/  :? for help
Glasgow Haskell Compiler, Version 8.2.1, stage 2 booted by GHC version 8.0.2
Using binary package database: C:\Users\micha\Desktop\GHC\ghc-8.2.1\lib\package.conf.d\package.cache
package flags []
loading package database C:\Users\micha\Desktop\GHC\ghc-8.2.1\lib\package.conf.d
wired-in package ghc-prim mapped to ghc-prim-0.5.1.0
wired-in package integer-gmp mapped to integer-gmp-1.0.1.0
wired-in package base mapped to base-4.10.0.0
wired-in package rts mapped to rts
wired-in package template-haskell mapped to template-haskell-2.12.0.0
wired-in package ghc mapped to ghc-8.2.1
wired-in package dph-seq not found.
wired-in package dph-par not found.
*** Parser [source]:
!!! Parser [source]: finished in 0.00 milliseconds, allocated 0.129 megabytes
*** Desugar:
*** Simplify [expr]:
!!! Simplify [expr]: finished in 0.00 milliseconds, allocated 0.109 megabytes
*** CorePrep [expr]:
!!! CorePrep [expr]: finished in 15.63 milliseconds, allocated 1.545 megabytes
*** ByteCodeGen [Ghci1]:
!!! ByteCodeGen [Ghci1]: finished in 0.00 milliseconds, allocated 0.132 megabytes
Access violation in generated code when reading 00000000046710f6

From tamar at zhox.com  Sat Oct 21 02:54:49 2017
From: tamar at zhox.com (Tamar Christina)
Date: Sat, 21 Oct 2017 02:54:49 +0000
Subject: Getting segmentation fault on stack/cabal -any command,
 including stack --install-ghc, On windows.
In-Reply-To: <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
 <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
 <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>
Message-ID: <15f3cdabe67.f6a64d5360193.9056460721006035666@zhox.com>




 ---- On Fri, 20 Oct 2017 23:51:43 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ---- 
 > Previously to FCU, the issue was also occuring with ghc8.0.2(a), however, it would appear that it is working again.
 > I have provided the output of ghci -v3 *8.2.1). 

Thanks, this is quite early on, does <ghc folder>\mingw\bin\gcc --version work?

 > I was unable to run procdump, it was giving me directory does not exist, even when placed in the bin folder.

Hmm that's odd, and you're running this from a normal cmd prompt? a dump would really be helpful here.

 > 
 > On Fri, Oct 20, 2017 at 4:08 PM Tamar Christina <tamar at zhox.com> wrote:
 > -- 
 > Michael McCulloch
 >  c: (403) 629-9645
 >  e: michael.james.mcculloch at gmail.com 
 >   Hi Michael,
 >  
 >  Does this happen only with 8.2.1?
 >  
 >  Can you try a clean vanilla GHC?
 >  https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz
 >  
 >  just to rule out any issues with toolings.
 >  
 >  if it still happens, does ghci -v3 show anything?
 >  
 >  if it still crashes can you run procdump on GHC directly and return the dump?
 >  
 >  https://docs.microsoft.com/en-us/sysinternals/downloads/procdump
 >  
 >  with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"
 >  
 >  Thanks,
 >  Tamar
 >  
 >  
 >   ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ----
 >   > Hello.
 >   > After searching around I can't find people with a similar issue (Maybe I'm looking in the wrong places?).
 >   > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal 2.0.0.0. Windows 10 Fall Creators Update( This issue was also occurring pre FCU). The issue also occurs with 8.0.2a
 >   > Prior to FCU, I could run ghci directly, but now i get:
 >   >     Access violation in generated code when reading 00000000046710f6
 >   > Can anyone help me out?--
 >   > Michael McCulloch
 >   >  c: (403) 629-9645
 >   >  e: michael.james.mcculloch at gmail.com
 >   >   _______________________________________________
 >   > Glasgow-haskell-users mailing list
 >   > Glasgow-haskell-users at haskell.org
 >   > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 >   >
 >  
 >  
 >  



From tamar at zhox.com  Sat Oct 21 19:54:12 2017
From: tamar at zhox.com (Tamar Christina)
Date: Sat, 21 Oct 2017 19:54:12 +0000
Subject: Getting segmentation fault on stack/cabal -any command,
 including stack --install-ghc, On windows.
In-Reply-To: <15f3cdabe67.f6a64d5360193.9056460721006035666@zhox.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
 <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
 <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>
 <15f3cdabe67.f6a64d5360193.9056460721006035666@zhox.com>
Message-ID: <15f408003e8.1237e6989107803.6156525254112938362@zhox.com>

Hi,

Could you try https://1drv.ms/u/s!AuQz_u-9HaJPmcQRFveWa9dMBi77hg ?

If you can still reproduce this issue with this build start with
+RTS --generate-crash-dumps

and send the dump it creates. Note that this is a pre-release version of GHC 8.4
so some packages may not compile without updating version bounds.

Tamar


 ---- On Sat, 21 Oct 2017 02:54:49 +0000 Tamar Christina <tamar at zhox.com> wrote ---- 
 > 
 > 
 > 
 >  ---- On Fri, 20 Oct 2017 23:51:43 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ---- 
 >  > Previously to FCU, the issue was also occuring with ghc8.0.2(a), however, it would appear that it is working again.
 >  > I have provided the output of ghci -v3 *8.2.1). 
 > 
 > Thanks, this is quite early on, does <ghc folder>\mingw\bin\gcc --version work?
 > 
 >  > I was unable to run procdump, it was giving me directory does not exist, even when placed in the bin folder.
 > 
 > Hmm that's odd, and you're running this from a normal cmd prompt? a dump would really be helpful here.
 > 
 >  > 
 >  > On Fri, Oct 20, 2017 at 4:08 PM Tamar Christina <tamar at zhox.com> wrote:
 >  > -- 
 >  > Michael McCulloch
 >  >  c: (403) 629-9645
 >  >  e: michael.james.mcculloch at gmail.com 
 >  >   Hi Michael,
 >  >  
 >  >  Does this happen only with 8.2.1?
 >  >  
 >  >  Can you try a clean vanilla GHC?
 >  >  https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz
 >  >  
 >  >  just to rule out any issues with toolings.
 >  >  
 >  >  if it still happens, does ghci -v3 show anything?
 >  >  
 >  >  if it still crashes can you run procdump on GHC directly and return the dump?
 >  >  
 >  >  https://docs.microsoft.com/en-us/sysinternals/downloads/procdump
 >  >  
 >  >  with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"
 >  >  
 >  >  Thanks,
 >  >  Tamar
 >  >  
 >  >  
 >  >   ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ----
 >  >   > Hello.
 >  >   > After searching around I can't find people with a similar issue (Maybe I'm looking in the wrong places?).
 >  >   > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal 2.0.0.0. Windows 10 Fall Creators Update( This issue was also occurring pre FCU). The issue also occurs with 8.0.2a
 >  >   > Prior to FCU, I could run ghci directly, but now i get:
 >  >   >     Access violation in generated code when reading 00000000046710f6
 >  >   > Can anyone help me out?--
 >  >   > Michael McCulloch
 >  >   >  c: (403) 629-9645
 >  >   >  e: michael.james.mcculloch at gmail.com
 >  >   >   _______________________________________________
 >  >   > Glasgow-haskell-users mailing list
 >  >   > Glasgow-haskell-users at haskell.org
 >  >   > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 >  >   >
 >  >  
 >  >  
 >  >  
 > 
 > 
 > _______________________________________________
 > Glasgow-haskell-users mailing list
 > Glasgow-haskell-users at haskell.org
 > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 > 



From michael.james.mcculloch at gmail.com  Sat Oct 21 20:05:34 2017
From: michael.james.mcculloch at gmail.com (Michael McCulloch)
Date: Sat, 21 Oct 2017 20:05:34 +0000
Subject: Getting segmentation fault on stack/cabal -any command, including
 stack --install-ghc, On windows.
In-Reply-To: <15f408003e8.1237e6989107803.6156525254112938362@zhox.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
 <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
 <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>
 <15f3cdabe67.f6a64d5360193.9056460721006035666@zhox.com>
 <15f408003e8.1237e6989107803.6156525254112938362@zhox.com>
Message-ID: <CAFL2cnPVMYLu=vtUUGE7-kgxToUbAMVdVEHC09ydb0n3Ox66Mw@mail.gmail.com>

Hi,

\ghc-8.2.1\mingw\bin\gcc --version produced no errors.

the ghc 8.4 release you sent produced no errors as well.

I have included the procdump output as well, in case it helps, same error
mentioned before.

On Sat, Oct 21, 2017 at 1:54 PM Tamar Christina <tamar at zhox.com> wrote:

> Hi,
>
> Could you try https://1drv.ms/u/s!AuQz_u-9HaJPmcQRFveWa9dMBi77hg ?
>
> If you can still reproduce this issue with this build start with
> +RTS --generate-crash-dumps
>
> and send the dump it creates. Note that this is a pre-release version of
> GHC 8.4
> so some packages may not compile without updating version bounds.
>
> Tamar
>
>
>  ---- On Sat, 21 Oct 2017 02:54:49 +0000 Tamar Christina <tamar at zhox.com>
> wrote ----
>  >
>  >
>  >
>  >  ---- On Fri, 20 Oct 2017 23:51:43 +0000 Michael McCulloch <
> michael.james.mcculloch at gmail.com> wrote ----
>  >  > Previously to FCU, the issue was also occuring with ghc8.0.2(a),
> however, it would appear that it is working again.
>  >  > I have provided the output of ghci -v3 *8.2.1).
>  >
>  > Thanks, this is quite early on, does <ghc folder>\mingw\bin\gcc
> --version work?
>  >
>  >  > I was unable to run procdump, it was giving me directory does not
> exist, even when placed in the bin folder.
>  >
>  > Hmm that's odd, and you're running this from a normal cmd prompt? a
> dump would really be helpful here.
>  >
>  >  >
>  >  > On Fri, Oct 20, 2017 at 4:08 PM Tamar Christina <tamar at zhox.com>
> wrote:
>  >  > --
>  >  > Michael McCulloch
>  >  >  c: (403) 629-9645
>  >  >  e: michael.james.mcculloch at gmail.com
>  >  >   Hi Michael,
>  >  >
>  >  >  Does this happen only with 8.2.1?
>  >  >
>  >  >  Can you try a clean vanilla GHC?
>  >  >
> https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz
>  >  >
>  >  >  just to rule out any issues with toolings.
>  >  >
>  >  >  if it still happens, does ghci -v3 show anything?
>  >  >
>  >  >  if it still crashes can you run procdump on GHC directly and return
> the dump?
>  >  >
>  >  >  https://docs.microsoft.com/en-us/sysinternals/downloads/procdump
>  >  >
>  >  >  with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"
>  >  >
>  >  >  Thanks,
>  >  >  Tamar
>  >  >
>  >  >
>  >  >   ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <
> michael.james.mcculloch at gmail.com> wrote ----
>  >  >   > Hello.
>  >  >   > After searching around I can't find people with a similar issue
> (Maybe I'm looking in the wrong places?).
>  >  >   > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal
> 2.0.0.0. Windows 10 Fall Creators Update( This issue was also occurring pre
> FCU). The issue also occurs with 8.0.2a
>  >  >   > Prior to FCU, I could run ghci directly, but now i get:
>  >  >   >     Access violation in generated code when reading
> 00000000046710f6
>  >  >   > Can anyone help me out?--
>  >  >   > Michael McCulloch
>  >  >   >  c: (403) 629-9645
>  >  >   >  e: michael.james.mcculloch at gmail.com
>  >  >   >   _______________________________________________
>  >  >   > Glasgow-haskell-users mailing list
>  >  >   > Glasgow-haskell-users at haskell.org
>  >  >   >
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>  >  >   >
>  >  >
>  >  >
>  >  >
>  >
>  >
>  > _______________________________________________
>  > Glasgow-haskell-users mailing list
>  > Glasgow-haskell-users at haskell.org
>  > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>  >
>
>
> --

Michael McCulloch

c: (403) 629-9645
e: michael.james.mcculloch at gmail.com
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C:\Users\micha\Desktop\ghc-8.2.1\bin>dir
 Volume in drive C has no label.
 Volume Serial Number is FECE-599C

 Directory of C:\Users\micha\Desktop\ghc-8.2.1\bin

2017-10-21  01:58 PM    <DIR>          .
2017-10-21  01:58 PM    <DIR>          ..
2017-07-22  12:40 AM           136,141 ghc-8.2.1.exe
2017-07-22  12:40 AM         9,038,773 ghc-pkg.exe
2017-07-22  12:40 AM        91,255,510 ghc.exe
2017-07-22  12:40 AM           397,919 ghci-8.2.1.exe
2017-07-22  12:40 AM           397,919 ghci.exe
2017-07-22  12:40 AM                56 ghcii-8.2.1.sh
2017-07-22  12:40 AM                56 ghcii.sh
2017-07-22  12:40 AM           136,141 haddock-8.2.1.exe
2017-07-22  12:40 AM        91,937,968 haddock.exe
2017-07-22  12:40 AM           178,289 hp2ps.exe
2017-07-22  12:40 AM         8,191,010 hpc.exe
2017-07-22  12:40 AM         7,623,348 hsc2hs.exe
2017-10-20  05:25 PM           651,424 procdump.exe
2017-10-20  05:25 PM           341,672 procdump64.exe
2017-07-22  12:40 AM         6,539,750 runghc.exe
2017-07-22  12:40 AM         6,539,750 runhaskell.exe
              16 File(s)    223,365,726 bytes
               2 Dir(s)  189,040,590,848 bytes free

C:\Users\micha\Desktop\ghc-8.2.1\bin>procdump.exe -e 1 -x ghc.exe --interactive

ProcDump v9.0 - Sysinternals process dump utility
Copyright (C) 2009-2017 Mark Russinovich and Andrew Richards
Sysinternals - www.sysinternals.com


The directory does not exist: C:\Users\micha\Desktop\ghc-8.2.1\bin\ghc.exe

From tamar at zhox.com  Sat Oct 21 22:57:55 2017
From: tamar at zhox.com (Tamar Christina)
Date: Sat, 21 Oct 2017 22:57:55 +0000
Subject: Getting segmentation fault on stack/cabal -any command,
 including stack --install-ghc, On windows.
In-Reply-To: <CAFL2cnPVMYLu=vtUUGE7-kgxToUbAMVdVEHC09ydb0n3Ox66Mw@mail.gmail.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
 <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
 <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>
 <15f3cdabe67.f6a64d5360193.9056460721006035666@zhox.com>
 <15f408003e8.1237e6989107803.6156525254112938362@zhox.com>
 <CAFL2cnPVMYLu=vtUUGE7-kgxToUbAMVdVEHC09ydb0n3Ox66Mw@mail.gmail.com>
Message-ID: <15f412835e5.105f778c8111338.9000374073030178384@zhox.com>

Ah, sorry,

try "procdump -e 1 -ma -x . <pathtobinfolder>\ghc --interactive"

the arguments to procdump changed.

It's good that it's fixed in 8.4 at least, but would be good to know what it is.

Could you also try the rc for 8.2.2?

https://downloads.haskell.org/~ghc/8.2.2-rc1/ghc-8.2.1.20170929-x86_64-unknown-mingw32.tar.xz


 ---- On Sat, 21 Oct 2017 20:05:34 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ---- 
 > Hi,
 > \ghc-8.2.1\mingw\bin\gcc --version produced no errors.
 > the ghc 8.4 release you sent produced no errors as well.
 > I have included the procdump output as well, in case it helps, same error mentioned before.
 > 
 > On Sat, Oct 21, 2017 at 1:54 PM Tamar Christina <tamar at zhox.com> wrote:
 > -- 
 > Michael McCulloch
 >  c: (403) 629-9645
 >  e: michael.james.mcculloch at gmail.com 
 >   Hi,
 >  
 >  Could you try https://1drv.ms/u/s!AuQz_u-9HaJPmcQRFveWa9dMBi77hg ?
 >  
 >  If you can still reproduce this issue with this build start with
 >  +RTS --generate-crash-dumps
 >  
 >  and send the dump it creates. Note that this is a pre-release version of GHC 8.4
 >  so some packages may not compile without updating version bounds.
 >  
 >  Tamar
 >  
 >  
 >   ---- On Sat, 21 Oct 2017 02:54:49 +0000 Tamar Christina <tamar at zhox.com> wrote ----
 >   >
 >   >
 >   >
 >   >  ---- On Fri, 20 Oct 2017 23:51:43 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ----
 >   >  > Previously to FCU, the issue was also occuring with ghc8.0.2(a), however, it would appear that it is working again.
 >   >  > I have provided the output of ghci -v3 *8.2.1).
 >   >
 >   > Thanks, this is quite early on, does <ghc folder>\mingw\bin\gcc --version work?
 >   >
 >   >  > I was unable to run procdump, it was giving me directory does not exist, even when placed in the bin folder.
 >   >
 >   > Hmm that's odd, and you're running this from a normal cmd prompt? a dump would really be helpful here.
 >   >
 >   >  >
 >   >  > On Fri, Oct 20, 2017 at 4:08 PM Tamar Christina <tamar at zhox.com> wrote:
 >   >  > --
 >   >  > Michael McCulloch
 >   >  >  c: (403) 629-9645
 >   >  >  e: michael.james.mcculloch at gmail.com
 >   >  >   Hi Michael,
 >   >  >
 >   >  >  Does this happen only with 8.2.1?
 >   >  >
 >   >  >  Can you try a clean vanilla GHC?
 >   >  >  https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz
 >   >  >
 >   >  >  just to rule out any issues with toolings.
 >   >  >
 >   >  >  if it still happens, does ghci -v3 show anything?
 >   >  >
 >   >  >  if it still crashes can you run procdump on GHC directly and return the dump?
 >   >  >
 >   >  >  https://docs.microsoft.com/en-us/sysinternals/downloads/procdump
 >   >  >
 >   >  >  with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"
 >   >  >
 >   >  >  Thanks,
 >   >  >  Tamar
 >   >  >
 >   >  >
 >   >  >   ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ----
 >   >  >   > Hello.
 >   >  >   > After searching around I can't find people with a similar issue (Maybe I'm looking in the wrong places?).
 >   >  >   > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal 2.0.0.0. Windows 10 Fall Creators Update( This issue was also occurring pre FCU). The issue also occurs with 8.0.2a
 >   >  >   > Prior to FCU, I could run ghci directly, but now i get:
 >   >  >   >     Access violation in generated code when reading 00000000046710f6
 >   >  >   > Can anyone help me out?--
 >   >  >   > Michael McCulloch
 >   >  >   >  c: (403) 629-9645
 >   >  >   >  e: michael.james.mcculloch at gmail.com
 >   >  >   >   _______________________________________________
 >   >  >   > Glasgow-haskell-users mailing list
 >   >  >   > Glasgow-haskell-users at haskell.org
 >   >  >   > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 >   >  >   >
 >   >  >
 >   >  >
 >   >  >
 >   >
 >   >
 >   > _______________________________________________
 >   > Glasgow-haskell-users mailing list
 >   > Glasgow-haskell-users at haskell.org
 >   > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 >   >
 >  
 >  
 >  



From michael.james.mcculloch at gmail.com  Sat Oct 21 23:24:11 2017
From: michael.james.mcculloch at gmail.com (Michael McCulloch)
Date: Sat, 21 Oct 2017 23:24:11 +0000
Subject: Getting segmentation fault on stack/cabal -any command, including
 stack --install-ghc, On windows.
In-Reply-To: <15f412835e5.105f778c8111338.9000374073030178384@zhox.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
 <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
 <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>
 <15f3cdabe67.f6a64d5360193.9056460721006035666@zhox.com>
 <15f408003e8.1237e6989107803.6156525254112938362@zhox.com>
 <CAFL2cnPVMYLu=vtUUGE7-kgxToUbAMVdVEHC09ydb0n3Ox66Mw@mail.gmail.com>
 <15f412835e5.105f778c8111338.9000374073030178384@zhox.com>
Message-ID: <CAFL2cnNYcrzfrNhMx_Ye=V3-Q3rd_12gaDLbOnC2rNKGxH9oHQ@mail.gmail.com>

Here you go, the dumps for both.

https://1drv.ms/u/s!AhjXZn763iGDtSiB7bBfJCmOfxQO


On Sat, Oct 21, 2017 at 4:57 PM Tamar Christina <tamar at zhox.com> wrote:

> Ah, sorry,
>
> try "procdump -e 1 -ma -x . <pathtobinfolder>\ghc --interactive"
>
> the arguments to procdump changed.
>
> It's good that it's fixed in 8.4 at least, but would be good to know what
> it is.
>
> Could you also try the rc for 8.2.2?
>
>
> https://downloads.haskell.org/~ghc/8.2.2-rc1/ghc-8.2.1.20170929-x86_64-unknown-mingw32.tar.xz
>
>
>  ---- On Sat, 21 Oct 2017 20:05:34 +0000 Michael McCulloch <
> michael.james.mcculloch at gmail.com> wrote ----
>  > Hi,
>  > \ghc-8.2.1\mingw\bin\gcc --version produced no errors.
>  > the ghc 8.4 release you sent produced no errors as well.
>  > I have included the procdump output as well, in case it helps, same
> error mentioned before.
>  >
>  > On Sat, Oct 21, 2017 at 1:54 PM Tamar Christina <tamar at zhox.com> wrote:
>  > --
>  > Michael McCulloch
>  >  c: (403) 629-9645
>  >  e: michael.james.mcculloch at gmail.com
>  >   Hi,
>  >
>  >  Could you try https://1drv.ms/u/s!AuQz_u-9HaJPmcQRFveWa9dMBi77hg ?
>  >
>  >  If you can still reproduce this issue with this build start with
>  >  +RTS --generate-crash-dumps
>  >
>  >  and send the dump it creates. Note that this is a pre-release version
> of GHC 8.4
>  >  so some packages may not compile without updating version bounds.
>  >
>  >  Tamar
>  >
>  >
>  >   ---- On Sat, 21 Oct 2017 02:54:49 +0000 Tamar Christina <
> tamar at zhox.com> wrote ----
>  >   >
>  >   >
>  >   >
>  >   >  ---- On Fri, 20 Oct 2017 23:51:43 +0000 Michael McCulloch <
> michael.james.mcculloch at gmail.com> wrote ----
>  >   >  > Previously to FCU, the issue was also occuring with ghc8.0.2(a),
> however, it would appear that it is working again.
>  >   >  > I have provided the output of ghci -v3 *8.2.1).
>  >   >
>  >   > Thanks, this is quite early on, does <ghc folder>\mingw\bin\gcc
> --version work?
>  >   >
>  >   >  > I was unable to run procdump, it was giving me directory does
> not exist, even when placed in the bin folder.
>  >   >
>  >   > Hmm that's odd, and you're running this from a normal cmd prompt? a
> dump would really be helpful here.
>  >   >
>  >   >  >
>  >   >  > On Fri, Oct 20, 2017 at 4:08 PM Tamar Christina <tamar at zhox.com>
> wrote:
>  >   >  > --
>  >   >  > Michael McCulloch
>  >   >  >  c: (403) 629-9645
>  >   >  >  e: michael.james.mcculloch at gmail.com
>  >   >  >   Hi Michael,
>  >   >  >
>  >   >  >  Does this happen only with 8.2.1?
>  >   >  >
>  >   >  >  Can you try a clean vanilla GHC?
>  >   >  >
> https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz
>  >   >  >
>  >   >  >  just to rule out any issues with toolings.
>  >   >  >
>  >   >  >  if it still happens, does ghci -v3 show anything?
>  >   >  >
>  >   >  >  if it still crashes can you run procdump on GHC directly and
> return the dump?
>  >   >  >
>  >   >  >
> https://docs.microsoft.com/en-us/sysinternals/downloads/procdump
>  >   >  >
>  >   >  >  with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"
>  >   >  >
>  >   >  >  Thanks,
>  >   >  >  Tamar
>  >   >  >
>  >   >  >
>  >   >  >   ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <
> michael.james.mcculloch at gmail.com> wrote ----
>  >   >  >   > Hello.
>  >   >  >   > After searching around I can't find people with a similar
> issue (Maybe I'm looking in the wrong places?).
>  >   >  >   > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal
> 2.0.0.0. Windows 10 Fall Creators Update( This issue was also occurring pre
> FCU). The issue also occurs with 8.0.2a
>  >   >  >   > Prior to FCU, I could run ghci directly, but now i get:
>  >   >  >   >     Access violation in generated code when reading
> 00000000046710f6
>  >   >  >   > Can anyone help me out?--
>  >   >  >   > Michael McCulloch
>  >   >  >   >  c: (403) 629-9645
>  >   >  >   >  e: michael.james.mcculloch at gmail.com
>  >   >  >   >   _______________________________________________
>  >   >  >   > Glasgow-haskell-users mailing list
>  >   >  >   > Glasgow-haskell-users at haskell.org
>  >   >  >   >
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>  >   >  >   >
>  >   >  >
>  >   >  >
>  >   >  >
>  >   >
>  >   >
>  >   > _______________________________________________
>  >   > Glasgow-haskell-users mailing list
>  >   > Glasgow-haskell-users at haskell.org
>  >   >
> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>  >   >
>  >
>  >
>  >
>
>
> --

Michael McCulloch

c: (403) 629-9645
e: michael.james.mcculloch at gmail.com
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From tamar at zhox.com  Sun Oct 22 08:51:02 2017
From: tamar at zhox.com (Tamar Christina)
Date: Sun, 22 Oct 2017 08:51:02 +0000
Subject: Getting segmentation fault on stack/cabal -any command,
 including stack --install-ghc, On windows.
In-Reply-To: <CAFL2cnNYcrzfrNhMx_Ye=V3-Q3rd_12gaDLbOnC2rNKGxH9oHQ@mail.gmail.com>
References: <CAFL2cnMTSKb8ktt=eTyJ7+DcyVn04R4M5T9iApD3fkjd7yePrg@mail.gmail.com>
 <15f3bd466bd.1085e26a348121.3777293386395531776@zhox.com>
 <CAFL2cnMwoS32G1DZtv7oEVmwD5Cj7SHQ9Wm9fOAkmX_3XW5oyw@mail.gmail.com>
 <15f3cdabe67.f6a64d5360193.9056460721006035666@zhox.com>
 <15f408003e8.1237e6989107803.6156525254112938362@zhox.com>
 <CAFL2cnPVMYLu=vtUUGE7-kgxToUbAMVdVEHC09ydb0n3Ox66Mw@mail.gmail.com>
 <15f412835e5.105f778c8111338.9000374073030178384@zhox.com>
 <CAFL2cnNYcrzfrNhMx_Ye=V3-Q3rd_12gaDLbOnC2rNKGxH9oHQ@mail.gmail.com>
Message-ID: <15f4347391e.cd7ea972123045.3392304103205955551@zhox.com>

Hi Michael,

It seems your problem is with HitmanPro that you have installed.

ExceptionAddress: 00007ffcc2b368ce (ntdll!RtlVirtualUnwind+0x000000000000001e)
   ExceptionCode: c0000005 (Access violation)
  ExceptionFlags: 00000000
NumberParameters: 2
   Parameter[0]: 0000000000000000
   Parameter[1]: 00000000046710f6
Attempt to read from address 00000000046710f6
0:000> lmvm hmpalert
Browse full module list
start             end                 module name
00007ffc`ba4b0000 00007ffc`ba595000   hmpalert   (export symbols)       hmpalert.dll
    Loaded symbol image file: hmpalert.dll
    Image path: C:\Windows\System32\hmpalert.dll
    Image name: hmpalert.dll
    Browse all global symbols  functions  data
    Timestamp:        Mon Jul 17 15:53:17 2017 (596CCF5D)
    CheckSum:         000F490C
    ImageSize:        000E5000
    File version:     3.6.8.604
    Product version:  3.6.8.604
    File flags:       0 (Mask 3F)
    File OS:          40004 NT Win32
    File type:        2.0 Dll
    File date:        00000000.00000000
    Translations:     0400.04b0
    CompanyName:      SurfRight B.V.
    ProductName:      HitmanPro.Alert
    InternalName:     hmpalert.dll
    OriginalFilename: hmpalert_x64.dll
    ProductVersion:   3.6.8.604
    FileVersion:      3.6.8.604
    FileDescription:  HitmanPro.Alert 64-bit Support Library
    LegalCopyright:   © 2013-2017 SurfRight, a Sophos company
    Comments:         Incorporates Threatstar Exploit Mitigation Platform (EMP)

It seems HitmanPro is injecting itself into GHC's address space by throwing a signal
and forcing the process to halt. GHC prior to the upcoming 8.4 release interprets this
as one of it's needed dependencies crashing and so aborts the process before Hitman can
handle the signal it threw.

Until GHC 8.4 comes out, to get it working you should exclude the GHC binaries from Hitman's scanning.

Cheers,
Tamar

 ---- On Sat, 21 Oct 2017 23:24:11 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ---- 
 > Here you go, the dumps for both.
 > https://1drv.ms/u/s!AhjXZn763iGDtSiB7bBfJCmOfxQO
 > 
 > On Sat, Oct 21, 2017 at 4:57 PM Tamar Christina <tamar at zhox.com> wrote:
 > -- 
 > Michael McCulloch
 >  c: (403) 629-9645
 >  e: michael.james.mcculloch at gmail.com 
 >   Ah, sorry,
 >  
 >  try "procdump -e 1 -ma -x . <pathtobinfolder>\ghc --interactive"
 >  
 >  the arguments to procdump changed.
 >  
 >  It's good that it's fixed in 8.4 at least, but would be good to know what it is.
 >  
 >  Could you also try the rc for 8.2.2?
 >  
 >  https://downloads.haskell.org/~ghc/8.2.2-rc1/ghc-8.2.1.20170929-x86_64-unknown-mingw32.tar.xz
 >  
 >  
 >   ---- On Sat, 21 Oct 2017 20:05:34 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ----
 >   > Hi,
 >   > \ghc-8.2.1\mingw\bin\gcc --version produced no errors.
 >   > the ghc 8.4 release you sent produced no errors as well.
 >   > I have included the procdump output as well, in case it helps, same error mentioned before.
 >   >
 >   > On Sat, Oct 21, 2017 at 1:54 PM Tamar Christina <tamar at zhox.com> wrote:
 >   > --
 >   > Michael McCulloch
 >   >  c: (403) 629-9645
 >   >  e: michael.james.mcculloch at gmail.com
 >   >   Hi,
 >   >
 >   >  Could you try https://1drv.ms/u/s!AuQz_u-9HaJPmcQRFveWa9dMBi77hg ?
 >   >
 >   >  If you can still reproduce this issue with this build start with
 >   >  +RTS --generate-crash-dumps
 >   >
 >   >  and send the dump it creates. Note that this is a pre-release version of GHC 8.4
 >   >  so some packages may not compile without updating version bounds.
 >   >
 >   >  Tamar
 >   >
 >   >
 >   >   ---- On Sat, 21 Oct 2017 02:54:49 +0000 Tamar Christina <tamar at zhox.com> wrote ----
 >   >   >
 >   >   >
 >   >   >
 >   >   >  ---- On Fri, 20 Oct 2017 23:51:43 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ----
 >   >   >  > Previously to FCU, the issue was also occuring with ghc8.0.2(a), however, it would appear that it is working again.
 >   >   >  > I have provided the output of ghci -v3 *8.2.1).
 >   >   >
 >   >   > Thanks, this is quite early on, does <ghc folder>\mingw\bin\gcc --version work?
 >   >   >
 >   >   >  > I was unable to run procdump, it was giving me directory does not exist, even when placed in the bin folder.
 >   >   >
 >   >   > Hmm that's odd, and you're running this from a normal cmd prompt? a dump would really be helpful here.
 >   >   >
 >   >   >  >
 >   >   >  > On Fri, Oct 20, 2017 at 4:08 PM Tamar Christina <tamar at zhox.com> wrote:
 >   >   >  > --
 >   >   >  > Michael McCulloch
 >   >   >  >  c: (403) 629-9645
 >   >   >  >  e: michael.james.mcculloch at gmail.com
 >   >   >  >   Hi Michael,
 >   >   >  >
 >   >   >  >  Does this happen only with 8.2.1?
 >   >   >  >
 >   >   >  >  Can you try a clean vanilla GHC?
 >   >   >  >  https://downloads.haskell.org/~ghc/8.2.1/ghc-8.2.1-x86_64-unknown-mingw32.tar.xz
 >   >   >  >
 >   >   >  >  just to rule out any issues with toolings.
 >   >   >  >
 >   >   >  >  if it still happens, does ghci -v3 show anything?
 >   >   >  >
 >   >   >  >  if it still crashes can you run procdump on GHC directly and return the dump?
 >   >   >  >
 >   >   >  >  https://docs.microsoft.com/en-us/sysinternals/downloads/procdump
 >   >   >  >
 >   >   >  >  with "procdump -e 1 -x <pathtobinfolder>\ghc --interactive"
 >   >   >  >
 >   >   >  >  Thanks,
 >   >   >  >  Tamar
 >   >   >  >
 >   >   >  >
 >   >   >  >   ---- On Fri, 20 Oct 2017 14:02:31 +0000 Michael McCulloch <michael.james.mcculloch at gmail.com> wrote ----
 >   >   >  >   > Hello.
 >   >   >  >   > After searching around I can't find people with a similar issue (Maybe I'm looking in the wrong places?).
 >   >   >  >   > I installed Haskell platform 8.2.1, using Stack 1.5.1, Cabal 2.0.0.0. Windows 10 Fall Creators Update( This issue was also occurring pre FCU). The issue also occurs with 8.0.2a
 >   >   >  >   > Prior to FCU, I could run ghci directly, but now i get:
 >   >   >  >   >     Access violation in generated code when reading 00000000046710f6
 >   >   >  >   > Can anyone help me out?--
 >   >   >  >   > Michael McCulloch
 >   >   >  >   >  c: (403) 629-9645
 >   >   >  >   >  e: michael.james.mcculloch at gmail.com
 >   >   >  >   >   _______________________________________________
 >   >   >  >   > Glasgow-haskell-users mailing list
 >   >   >  >   > Glasgow-haskell-users at haskell.org
 >   >   >  >   > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 >   >   >  >   >
 >   >   >  >
 >   >   >  >
 >   >   >  >
 >   >   >
 >   >   >
 >   >   > _______________________________________________
 >   >   > Glasgow-haskell-users mailing list
 >   >   > Glasgow-haskell-users at haskell.org
 >   >   > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
 >   >   >
 >   >
 >   >
 >   >
 >  
 >  
 >  



From Sebastien.Hinderer at inria.fr  Mon Oct 30 15:17:38 2017
From: Sebastien.Hinderer at inria.fr (=?utf-8?Q?S=C3=A9bastien?= Hinderer)
Date: Mon, 30 Oct 2017 16:17:38 +0100
Subject: How does GHC's testsuite work?
Message-ID: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>

Dear all,

I am a member of OCaml's developement team. More specifically, I am
working on a test-driver for the OCaml compiler, which will be part of
OCaml's 4.06 release.

I am currently writing an article to describe the tool and its
principles. In this article, I would like to also talk about how other
compilers' testsuites are handled and loking how things are done in GHC
is natural.

In OCaml, our testsuite essentially consist in whole programs that
we compile and run, checking that the compilation and execution results
match the expected ones.

>From what I could see from GHC's testsuite, it seemed to me that it uses
Python to drive the tests. I also understood that the testsuite has
tests that are more kind of unit-tests, in the .T file. Am I correct
here? Or do you guys also have whole program tests?
If you do, how do you compile and run them?

Any comment / hint on this aspect of the test harness' design would be
really helpful.

Many thanks in advance,

Sébastien.






From ezyang at mit.edu  Mon Oct 30 15:25:34 2017
From: ezyang at mit.edu (Edward Z. Yang)
Date: Mon, 30 Oct 2017 11:25:34 -0400
Subject: How does GHC's testsuite work?
In-Reply-To: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
References: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
Message-ID: <1509377084-sup-897@sabre>

Actually, it's the reverse of what you said: like OCaml, GHC essentially
has ~no unit tests; it's entirely Haskell programs which we compile
(and sometimes run; a lot of tests are for the typechecker only so
we don't bother running those.)  The .T file is just a way of letting
the Python driver know what tests exist.

Edward

Excerpts from Sébastien Hinderer's message of 2017-10-30 16:17:38 +0100:
> Dear all,
> 
> I am a member of OCaml's developement team. More specifically, I am
> working on a test-driver for the OCaml compiler, which will be part of
> OCaml's 4.06 release.
> 
> I am currently writing an article to describe the tool and its
> principles. In this article, I would like to also talk about how other
> compilers' testsuites are handled and loking how things are done in GHC
> is natural.
> 
> In OCaml, our testsuite essentially consist in whole programs that
> we compile and run, checking that the compilation and execution results
> match the expected ones.
> 
> From what I could see from GHC's testsuite, it seemed to me that it uses
> Python to drive the tests. I also understood that the testsuite has
> tests that are more kind of unit-tests, in the .T file. Am I correct
> here? Or do you guys also have whole program tests?
> If you do, how do you compile and run them?
> 
> Any comment / hint on this aspect of the test harness' design would be
> really helpful.
> 
> Many thanks in advance,
> 
> Sébastien.
> 

From Sebastien.Hinderer at inria.fr  Mon Oct 30 15:39:24 2017
From: Sebastien.Hinderer at inria.fr (=?utf-8?Q?S=C3=A9bastien?= Hinderer)
Date: Mon, 30 Oct 2017 16:39:24 +0100
Subject: How does GHC's testsuite work?
In-Reply-To: <1509377084-sup-897@sabre>
References: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
 <1509377084-sup-897@sabre>
Message-ID: <20171030153924.ieik3ihqypfuff4o@pl-59055.rocqadm.inria.fr>

Dear Edward,

Many thanks for your prompt response!

Edward Z. Yang (2017/10/30 11:25 -0400):
> Actually, it's the reverse of what you said: like OCaml, GHC essentially
> has ~no unit tests; it's entirely Haskell programs which we compile
> (and sometimes run; a lot of tests are for the typechecker only so
> we don't bother running those.)  The .T file is just a way of letting
> the Python driver know what tests exist.

Oh okay! Would you be able to point me to just a few tests to get an
idea of a few typical situations, please?

One other question I forgot to ask: how do you deal with conditional
tests? For instance, if a test should be run only on some platforms? Or,
in OCaml we have tests for Fortran bindings that should be run only if a
Fortran compiler is available. How would you deal with such tests?

Thanks!

Sébastien.

From ezyang at mit.edu  Mon Oct 30 15:51:27 2017
From: ezyang at mit.edu (Edward Z. Yang)
Date: Mon, 30 Oct 2017 11:51:27 -0400
Subject: How does GHC's testsuite work?
In-Reply-To: <20171030153924.ieik3ihqypfuff4o@pl-59055.rocqadm.inria.fr>
References: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
 <1509377084-sup-897@sabre>
 <20171030153924.ieik3ihqypfuff4o@pl-59055.rocqadm.inria.fr>
Message-ID: <1509378576-sup-696@sabre>

Excerpts from Sébastien Hinderer's message of 2017-10-30 16:39:24 +0100:
> Dear Edward,
> 
> Many thanks for your prompt response!
> 
> Edward Z. Yang (2017/10/30 11:25 -0400):
> > Actually, it's the reverse of what you said: like OCaml, GHC essentially
> > has ~no unit tests; it's entirely Haskell programs which we compile
> > (and sometimes run; a lot of tests are for the typechecker only so
> > we don't bother running those.)  The .T file is just a way of letting
> > the Python driver know what tests exist.
> 
> Oh okay! Would you be able to point me to just a few tests to get an
> idea of a few typical situations, please?

For example:

    The metadata
    https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail/all.T

    The source file
    https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail/tcfail011.hs

    The expected error output
    https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail/tcfail011.stderr

> One other question I forgot to ask: how do you deal with conditional
> tests? For instance, if a test should be run only on some platforms? Or,
> in OCaml we have tests for Fortran bindings that should be run only if a
> Fortran compiler is available. How would you deal with such tests?

All managed inside the Python driver code.

Example:
https://github.com/ghc/ghc/blob/master/testsuite/tests/rts/all.T#L32

Edward

From mail at joachim-breitner.de  Mon Oct 30 17:44:14 2017
From: mail at joachim-breitner.de (Joachim Breitner)
Date: Mon, 30 Oct 2017 13:44:14 -0400
Subject: How does GHC's testsuite work?
In-Reply-To: <1509377084-sup-897@sabre>
References: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
 <1509377084-sup-897@sabre>
Message-ID: <1509385454.1273.26.camel@joachim-breitner.de>

Hi Sebastien,

I’m looking forward to your report, surely there will be some
interesting inspirations for us.

Am Montag, den 30.10.2017, 11:25 -0400 schrieb Edward Z. Yang:
> Actually, it's the reverse of what you said: like OCaml, GHC essentially
> has ~no unit tests; it's entirely Haskell programs which we compile
> (and sometimes run; a lot of tests are for the typechecker only so
> we don't bother running those.)  The .T file is just a way of letting
> the Python driver know what tests exist.

let me add that these tests rarely check the actual output of the
compiler (i.e. the program, or even the simplified code). Often it is
enough to check
 * whether the compile succeeds or fails as expected, or maybe
 * what messages the compiler prints.

In a few cases we do dump the complete intermediate code (-ddump-
simpl), but then the test case specifies a “normalization function”
that checks the output for a certain property, e.g. by grepping for
certain patterns.

The only real unit tests that I know of are these:
http://git.haskell.org/ghc.git/tree/HEAD:/testsuite/tests/callarity/unittest
These are effectively programs using “GHC-the-library”

Joachim


-- 
Joachim Breitner
  mail at joachim-breitner.de
  http://www.joachim-breitner.de/
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From Sebastien.Hinderer at inria.fr  Tue Oct 31 10:47:23 2017
From: Sebastien.Hinderer at inria.fr (=?utf-8?Q?S=C3=A9bastien?= Hinderer)
Date: Tue, 31 Oct 2017 11:47:23 +0100
Subject: How does GHC's testsuite work?
In-Reply-To: <1509385454.1273.26.camel@joachim-breitner.de>
References: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
 <1509377084-sup-897@sabre>
 <1509385454.1273.26.camel@joachim-breitner.de>
Message-ID: <20171031104723.irvmfbf5cthy3oka@pl-59055.rocqadm.inria.fr>

Dear Joachim,

Many thanks for your prompt, positive and encouraging response.

Joachim Breitner (2017/10/30 13:44 -0400):
> Hi Sebastien,
> 
> I’m looking forward to your report, surely there will be some
> interesting inspirations for us.

Thanks. Unfortunately, the paper has been written in French. i'll see
whether I can find the time to translate it into english soon. If I can
do so I'll definitely post a link.

> Am Montag, den 30.10.2017, 11:25 -0400 schrieb Edward Z. Yang:
> > Actually, it's the reverse of what you said: like OCaml, GHC essentially
> > has ~no unit tests; it's entirely Haskell programs which we compile
> > (and sometimes run; a lot of tests are for the typechecker only so
> > we don't bother running those.)  The .T file is just a way of letting
> > the Python driver know what tests exist.
> 
> let me add that these tests rarely check the actual output of the
> compiler (i.e. the program, or even the simplified code). Often it is
> enough to check
>  * whether the compile succeeds or fails as expected, or maybe
>  * what messages the compiler prints.

I see. I think it is quite similar for OCaml.

> In a few cases we do dump the complete intermediate code (-ddump-
> simpl), but then the test case specifies a “normalization function”
> that checks the output for a certain property, e.g. by grepping for
> certain patterns.

Got it, thanks. We also have options to pretty-print the few internal
representations we have, but as far as I know, we don't use any
normalization function in such cases and just make a diff with an
expected reference (yuk!).

> The only real unit tests that I know of are these:
> http://git.haskell.org/ghc.git/tree/HEAD:/testsuite/tests/callarity/unittest
> These are effectively programs using “GHC-the-library”

Okay, thanks!

Will come back with a link ASAP!

Sébastien.

From Sebastien.Hinderer at inria.fr  Tue Oct 31 10:51:18 2017
From: Sebastien.Hinderer at inria.fr (=?utf-8?Q?S=C3=A9bastien?= Hinderer)
Date: Tue, 31 Oct 2017 11:51:18 +0100
Subject: How does GHC's testsuite work?
In-Reply-To: <1509378576-sup-696@sabre>
References: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
 <1509377084-sup-897@sabre>
 <20171030153924.ieik3ihqypfuff4o@pl-59055.rocqadm.inria.fr>
 <1509378576-sup-696@sabre>
Message-ID: <20171031105118.ssjsym4iozimurh7@pl-59055.rocqadm.inria.fr>

Dear Edward,

Many thanks to you, too, for your prompt response.

Edward Z. Yang (2017/10/30 11:51 -0400):
> Excerpts from Sébastien Hinderer's message of 2017-10-30 16:39:24 +0100:
> > Dear Edward,
> > 
> > Many thanks for your prompt response!
> > 
> > Edward Z. Yang (2017/10/30 11:25 -0400):
> > > Actually, it's the reverse of what you said: like OCaml, GHC essentially
> > > has ~no unit tests; it's entirely Haskell programs which we compile
> > > (and sometimes run; a lot of tests are for the typechecker only so
> > > we don't bother running those.)  The .T file is just a way of letting
> > > the Python driver know what tests exist.
> > 
> > Oh okay! Would you be able to point me to just a few tests to get an
> > idea of a few typical situations, please?
> 
> For example:
> 
>     The metadata
>     https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail/all.T
> 
>     The source file
>     https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail/tcfail011.hs
> 
>     The expected error output
>     https://github.com/ghc/ghc/blob/master/testsuite/tests/typecheck/should_fail/tcfail011.stderr

Excellent, thanks! With these few hints I really got the understanding I
was looking for so I'm really grateful for that, thanks!

> > One other question I forgot to ask: how do you deal with conditional
> > tests? For instance, if a test should be run only on some platforms? Or,
> > in OCaml we have tests for Fortran bindings that should be run only if a
> > Fortran compiler is available. How would you deal with such tests?
> 
> All managed inside the Python driver code.
> 
> Example:
> https://github.com/ghc/ghc/blob/master/testsuite/tests/rts/all.T#L32

okay thanks, awesome!

Best wishes,

Sébastien.

From kahl at cas.mcmaster.ca  Tue Oct 31 14:31:19 2017
From: kahl at cas.mcmaster.ca (Wolfram Kahl)
Date: Tue, 31 Oct 2017 10:31:19 -0400
Subject: How does GHC's testsuite work?
In-Reply-To: <20171031105118.ssjsym4iozimurh7@pl-59055.rocqadm.inria.fr>
References: <20171030151738.tcn7d2gjgz3bkhcp@pl-59055.rocqadm.inria.fr>
 <1509377084-sup-897@sabre>
 <20171030153924.ieik3ihqypfuff4o@pl-59055.rocqadm.inria.fr>
 <1509378576-sup-696@sabre>
 <20171031105118.ssjsym4iozimurh7@pl-59055.rocqadm.inria.fr>
Message-ID: <20171031143119.GA11796@ritchie.cas.mcmaster.ca>

Cher Sébastien,

> Thanks. Unfortunately, the paper has been written in French.

No need to add ``Unfortunately''...  ;-)


> Will come back with a link ASAP!

I guess that many will agree with my opinion:
Links to French papers are welcome, too!


Amicalement,

Wolfram

From ben at well-typed.com  Tue Oct 31 18:15:24 2017
From: ben at well-typed.com (Ben Gamari)
Date: Tue, 31 Oct 2017 14:15:24 -0400
Subject: [ANNOUNCE] GHC 8.2.2 release candidate 2
Message-ID: <877evbuqtf.fsf@ben-laptop.smart-cactus.org>


Hello everyone,

The GHC team is very pleased to announce the second candidate of the
8.2.2 release of the Glasgow Haskell Compiler. Source and binary
distributions are available at

    https://downloads.haskell.org/~ghc/8.2.2-rc2/

This is the second and hopefully last of two release candidates leading
up the final 8.2.2 release. This release fixes approximately fifty bugs
present in 8.2.1. These most notably include,

 * A correctness issue resulting in segmentation faults in some
   FFI-users (#13707, #14346)

 * A correctness issue resulting in undefined behavior in some programs
   using STM (#14171)

 * A bug which may have manifested in segmentation faults in
   out-of-memory condition (#14329)

 * clearBit of Natural no longer bottoms (#13203)

 * A specialisation bug resulting in exponential blowup of compilation
   time in some specialisation-intensive programs (#14379)

 * ghc-pkg now works even in environments with misconfigured NFS mounts
   (#13945)

 * GHC again supports production of position-independent executables
   (#13702)

 * Better error messages around kind mismatches (#11198, #12373, #13530,
   #13610)

See [1] for the full list.

As always, please report any issues you encounter.

Happy testing,

- Ben


[1] https://ghc.haskell.org/trac/ghc/query?status=closed&milestone=8.2.2&col=id&col=summary&col=status&col=type&col=priority&col=milestone&col=component&order=priority
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From ben at well-typed.com  Tue Oct 31 18:15:24 2017
From: ben at well-typed.com (Ben Gamari)
Date: Tue, 31 Oct 2017 14:15:24 -0400
Subject: [ANNOUNCE] GHC 8.2.2 release candidate 3
Message-ID: <87h8u31b9x.fsf@ben-laptop.smart-cactus.org>


Hello everyone,

The GHC team is very pleased to announce the third candidate of the
8.2.2 release of the Glasgow Haskell Compiler. Source and binary
distributions are available at

    https://downloads.haskell.org/~ghc/8.2.2-rc3/

This is the third and last of three release candidates leading up the
final 8.2.2 release. This release fixes approximately fifty bugs present
in 8.2.1. These most notably include,

 * A correctness issue resulting in segmentation faults in some
   FFI-users (#13707, #14346)

 * A correctness issue resulting in undefined behavior in some programs
   using STM (#14171)

 * A bug which may have manifested in segmentation faults in
   out-of-memory condition (#14329)

 * clearBit of Natural no longer bottoms (#13203)

 * A specialisation bug resulting in exponential blowup of compilation
   time in some specialisation-intensive programs (#14379)

 * ghc-pkg now works even in environments with misconfigured NFS mounts
   (#13945)

 * GHC again supports production of position-independent executables
   (#13702)

 * Better error messages around kind mismatches (#11198, #12373, #13530,
   #13610)

See [1] for the full list.

Release candidate three contains only two patches not present in -rc2
but fixes a packaging issue which lead to unintentional downgrading the
process and Cabal libraries.

As always, please report any issues you encounter.

Happy testing,

- Ben

[1]
https://ghc.haskell.org/trac/ghc/query?status=closed&milestone=8.2.2&col=id&col=summary&col=status&col=type&col=priority&col=milestone&col=component&order=priority
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