Bug#1023649: ghc: FTBFS haskell-random powerpc (ghc Segmentation fault)

[Ilias Tsitsimpis]

Hi Adrian,

On Wed, Oct 04, 2023 at 11:59AM, John Paul Adrian Glaubitz wrote:
> > 2. An unregisterised GHC 9.0.2 is *also* broken on powerpc, producing 
> > code that overflows integers. We are also seeing unregisterised GHC
> > 9.4.6 on i386 being broken, since the tests for haskell-quickcheck fail
> > (see https://buildd.debian.org/status/package.php?p=haskell-quickcheck&suite=sid).
> > The plan for i386 is to registerise GHC and use the LLVM backend by
> > default (to avoid the baseline violation).
> 
> I see.

A small update here. I didn't manage to use the LLVM backend on i386,
seems to be broken [1].

Instead, I believe I have managed to fix unregisterised GHC on 32-bit,
by backporting these two patches [2] [3]. Can you try building an
unregisterised GHC 9.4.7 on powerpc and see if this resolves the issues
you have with integer overflows? Note that GHC 9.4.7 *with* the Hadrian
build system is now available on experimental.

[1] https://gitlab.haskell.org/ghc/ghc/-/issues/24018
[2] https://salsa.debian.org/haskell-team/DHG_packages/-/blob/a38be7c092b024de04280f0a72642baf283cea01/p/ghc/debian/patches/fix-32-bit-unreg
[3] https://salsa.debian.org/haskell-team/DHG_packages/-/blob/a38be7c092b024de04280f0a72642baf283cea01/p/ghc/debian/patches/fix-hs_cmpxchg64

-- 
Ilias