libraries/binary does not compile with ghc-7.7

Gabor Greif ggreif at
Wed Feb 20 21:28:20 CET 2013

On 2/20/13, Ian Lynagh <ian at> wrote:
> On Wed, Feb 20, 2013 at 04:57:25PM +0100, Gabor Greif wrote:
>> when bootstrapping with GHC-7.7 I get
> Note that if you want to use HEAD to build HEAD, then the only
> supported version is the one that you are building (e.g. you can use
> today's HEAD to build today's HEAD, but not to build tomorrow's HEAD).

Hi Ian,

this is interesting, I built with a week old 7.7, with today's one
there was no error.

>> Okay to push to master?
> As long as it would still build with 7.4, sure.

It does with ghc-7.4.2, so I pushed it to ghc-head. I think a submodule
update is in order, which I'll try to perform and come bad whining if it
does not work out :-)

The second patch needs a rework, I get this with 7.4.2:

  HC [stage 0] libraries/binary/dist-boot/build/Data/Binary/Builder/Base.o

    Warning: In the use of `unsafePerformIO'
             (imported from Foreign):
             Deprecated: "Use System.IO.Unsafe.unsafePerformIO
instead; This function will be removed in the next release"

So possibly a common fix for  >=7.4 is possible. I try to come up with one.

> But actually, GHC back at least as far as 7.4 shipped with binary, so I
> don't think we need to build it with the bootstrapping compiler any
> more. Does the build go through if you just remove binary from

Yeah, looks like binary is not needed (tried with a HEAD bootstrap).
Will confirm with ghc-7.4.2 and push when ok.

Thanks for the tips,


> Thanks
> Ian

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