JuicyPixels build panics on s390x ghc-8.4.4
When I try to build JuicyPixels-3.2.9.5 on Fedora s390x Linux, ghc-8.4.4 panics:
[ 9 of 30] Compiling Codec.Picture.ColorQuant ( src/Codec/Picture/ColorQuant.hs, dist/build/Codec/Picture/ColorQuant.o )
BUILDSTDERR: src/Codec/Picture/ColorQuant.hs:123:26: warning: [-Woverflowed-literals]
BUILDSTDERR: Literal 256 is out of the GHC.Word.Word8 range 0..255
BUILDSTDERR: |
BUILDSTDERR: 123 | (PixelRGB8 (r .&. (256 - dr)) (g .&. (256 - dg)) (b .&. (256 - db)))
BUILDSTDERR: | ^^^
BUILDSTDERR: src/Codec/Picture/ColorQuant.hs:123:45: warning: [-Woverflowed-literals]
BUILDSTDERR: Literal 256 is out of the GHC.Word.Word8 range 0..255
BUILDSTDERR: |
BUILDSTDERR: 123 | (PixelRGB8 (r .&. (256 - dr)) (g .&. (256 - dg)) (b .&. (256 - db)))
BUILDSTDERR: | ^^^
BUILDSTDERR: src/Codec/Picture/ColorQuant.hs:123:64: warning: [-Woverflowed-literals]
BUILDSTDERR: Literal 256 is out of the GHC.Word.Word8 range 0..255
BUILDSTDERR: |
BUILDSTDERR: 123 | (PixelRGB8 (r .&. (256 - dr)) (g .&. (256 - dg)) (b .&. (256 - db)))
BUILDSTDERR: | ^^^
BUILDSTDERR: ghc: panic! (the 'impossible' happened)
BUILDSTDERR: (GHC version 8.4.4 for s390x-ibm-linux):
BUILDSTDERR: pprStatics: float
BUILDSTDERR: F32
BUILDSTDERR: F32
BUILDSTDERR: I32
BUILDSTDERR: Call stack:
BUILDSTDERR: CallStack (from HasCallStack):
BUILDSTDERR: callStackDoc, called at compiler/utils/Outputable.hs:1150:37 in ghc:Outputable
BUILDSTDERR: pprPanic, called at compiler/cmm/PprC.hs:525:5 in ghc:PprC
BUILDSTDERR: Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
I would test on ghc-8.6.3 too, but I haven't been able to build ghc-8.6 yet on s390x (unregisterized on unregisterized): see issue 15913.