[Haskell-cafe] Bug in GHC or cabal-install?
Ivan Lazar Miljenovic
ivan.miljenovic at gmail.com
Tue Jun 6 22:53:20 UTC 2017
On 6 June 2017 at 23:27, Henk-Jan van Tuyl <b.vantuyl1 at upcmail.nl> wrote:
>
> versionBranch is still in base, but it is not compatible with Cabal 2.
You mean it isn't re-exported by Cabal-2?
Then maybe wxc's Setup.hs needs to explicitly import Data.Version from
base rather than relying upon the re-export.
>
> Regards,
> Henk-Jan van Tuyl
>
>
>
>
> On Tue, 06 Jun 2017 14:32:45 +0200, Ivan Lazar Miljenovic
> <ivan.miljenovic at gmail.com> wrote:
>
>> On 6 June 2017 at 21:13, Henk-Jan van Tuyl <hjgtuyl at chello.nl> wrote:
>>>
>>>
>>> You are right, versionBranch is from originally from base, but you are
>>> missing the point:
>>> package wxc compiles perfectly the first time, but, without anything
>>> being
>>> changed, does not compile the second time. By the way, I am using a cabal
>>> sandbox and as I said earlier, I am using a GHC release candidate.
>>
>>
>> And in that release candidate, does the version of base have
>> versionBranch in it?
>>
>> My guess is that a new version of Cabal is being used the second time,
>> which is compiled against the base that comes with that RC which is
>> missing versionBranch.
>>
>> (But since I don't have any GHC RC's I can't check it myself.)
>>
>
>
>
>>>
>>> Regards,
>>> Henk-Jan van Tuyl
>>>
>>>
>>>
>>> On Tue, 06 Jun 2017 00:33:40 +0200, Ivan Lazar Miljenovic
>>> <ivan.miljenovic at gmail.com> wrote:
>>>
>>>> On 6 June 2017 at 07:55, Henk-Jan van Tuyl <b.vantuyl1 at upcmail.nl>
>>>> wrote:
>>>>>
>>>>>
>>>>>
>>>>> wxc/setup.hs uses versionBranch from Cabal[0]; the function
>>>>> versionBranch
>>>>> is
>>>>> not in Cabal 2, that is why I added "Cabal < 2" to wxc.cabal. When
>>>>> installing wxc the first time, the right version of Cabal is picked,
>>>>> when
>>>>> "cabal install" is invoked a second time, GHC tries to compile
>>>>> wxc/setup.hs
>>>>> again, but with the wrong version of Cabal (note: the release candidate
>>>>> of
>>>>> GHC comes with Cabal 2)
>>>>>
>>>>> [0]
>>>>>
>>>>>
>>>>> https://hackage.haskell.org/package/Cabal-1.24.2.0/docs/Distribution-Make.html#v:versionBranch
>>>>
>>>>
>>>>
>>>> If you look at the source for this module, you'll see that it isn't
>>>> defined in there; it's actually from Data.Version in base.
>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Mon, 05 Jun 2017 04:58:05 +0200, Ivan Lazar Miljenovic
>>>>> <ivan.miljenovic at gmail.com> wrote:
>>>>>
>>>>>> I don't think it's a problem with Cabal, but the version of base going
>>>>>> by the error: versionBranch is from base, and that error message is
>>>>>> talking about compiling the setup.hs from wxc.
>>>>>>
>>>>>> On 5 June 2017 at 12:03, Henk-Jan van Tuyl <b.vantuyl1 at upcmail.nl>
>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> The strange thing is, that the right version of Cabal is picked, the
>>>>>>> first
>>>>>>> time wxc is compiled. But when invoking cabal-install the second
>>>>>>> time,
>>>>>>> the
>>>>>>> setup-depends section seems to be ignored (or at least the Cabal < 2
>>>>>>> part).
>>>>>>> This does not happen with GHC 8.0.2
>>>>>>>
>>>>>>> (By the way, cabal-install tries to compile setup.hs again, even
>>>>>>> though
>>>>>>> nothing has changed.)
>>>>>>>
>>>>>>> Regards,
>>>>>>> Henk-Jan van Tuyl
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Sun, 04 Jun 2017 13:39:17 +0200, Ivan Lazar Miljenovic
>>>>>>> <ivan.miljenovic at gmail.com> wrote:
>>>>>>>
>>>>>>>> This is from a limitation/bug with Cabal-the-library, in that there
>>>>>>>> are typically no dependency checks for custom Setup.[l]hs
>>>>>>>> configurations.
>>>>>>>>
>>>>>>>> wxc has such a custom one:
>>>>>>>> http://hackage.haskell.org/package/wxc-0.92.3.0/src/Setup.hs
>>>>>>>>
>>>>>>>> versionBranch is from Data.Version in base, and it appears that the
>>>>>>>> in
>>>>>>>> this GHC pre-release there's been a change in base that removed this
>>>>>>>> function.
>>>>>>>>
>>>>>>>> On 4 June 2017 at 19:45, Henk-Jan van Tuyl <hjgtuyl at chello.nl>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> L.S.,
>>>>>>>>>
>>>>>>>>> I am trying the prerelease of GHC, version 8.2.0.20170507
>>>>>>>>>
>>>>>>>>> I adapted wxHaskell to the new packages that come with the new GHC
>>>>>>>>> and
>>>>>>>>> it
>>>>>>>>> compiles now, but only the first time. If I compile it a second
>>>>>>>>> time,
>>>>>>>>> even
>>>>>>>>> if nothing has changed, the information from the custom-setup
>>>>>>>>> section
>>>>>>>>> of
>>>>>>>>> the wxc.cabal file seems to be forgotten. This section looks like
>>>>>>>>> this:
>>>>>>>>>
>>>>>>>>> custom-setup
>>>>>>>>> setup-depends:
>>>>>>>>> base,
>>>>>>>>> Cabal < 2,
>>>>>>>>> containers,
>>>>>>>>> bytestring,
>>>>>>>>> split,
>>>>>>>>> process,
>>>>>>>>> directory,
>>>>>>>>> filepath
>>>>>>>>> (I am using cabal-install 1.24.0.2)
>>>>>>>>>
>>>>>>>>> Output from the second time I try to install wxHaskell:
>>>>>>>>>
>>>>>>>>>> cabal install --force-reinstalls --reinstall wxdirect wxc wxcore
>>>>>>>>>> wx
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> [1 of 1] Compiling Main (
>>>>>>>>> X:\Temp\wxHaskell\wxcore\dist\setup\setup.hs,
>>>>>>>>> X:\Temp\wxHaskell\wxcore\dist\setup\Main.o )
>>>>>>>>> Linking X:\Temp\wxHaskell\wxcore\dist\setup\setup.exe ...
>>>>>>>>> [1 of 1] Compiling Main (
>>>>>>>>> X:\Temp\wxHaskell\wxc\dist\setup\setup.hs,
>>>>>>>>> X:\Temp\wxHaskell\wxc\dist\setup\Main.o )
>>>>>>>>>
>>>>>>>>> X:\Temp\wxHaskell\wxc\dist\setup\setup.hs:505:61: error:
>>>>>>>>> Variable not in scope: versionBranch ::
>>>>>>>>> Version
>>>>>>>>> ->
>>>>>>>>> [a0]
>>>>>>>>> |
>>>>>>>>> 505 | full_ver = (concat . intersperse "." . map show .
>>>>>>>>> versionBranch) ver
>>>>>>>>> |
>>>>>>>>> ^^^^^^^^^^^^^
>>>>>>>>>
>>>>>>>>> This error message indicates that the wrong version of Cabal (2.0)
>>>>>>>>> is
>>>>>>>>> used
>>>>>>>>> to compile the wxcore setup.hs
>>>>>>>>> It looks like a cabal-install bug, but this does not happen when I
>>>>>>>>> use GHC 8.0.2; should I write a GHC bug ticket?
>>>>>>>>>
>>>>>>>>> Regards,
>>>>>>>>> Henk-Jan van Tuyl
>
>
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> --
--
Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com
http://IvanMiljenovic.wordpress.com
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