panic: RegAllocLinear.getStackSlotFor: out of stack slots

[daniel.is.fischer]

Trying to cabal install the crypto library, I got the error:

[1 of 4] Compiling Codec.Utils      ( Codec/Utils.hs, dist/build/SHA1Test/SHA1Test-tmp/Codec/Utils.o )
[2 of 4] Compiling Data.Digest.SHA1 ( Data/Digest/SHA1.hs, dist/build/SHA1Test/SHA1Test-tmp/Data/Digest/SHA1.o )
[3 of 4] Compiling Codec.Text.Raw   ( Codec/Text/Raw.hs, dist/build/SHA1Test/SHA1Test-tmp/Codec/Text/Raw.o )
[4 of 4] Compiling Main             ( ./SHA1Test.hs, dist/build/SHA1Test/SHA1Test-tmp/Main.o )
ghc-6.8.3: panic! (the 'impossible' happened)
  (GHC version 6.8.3 for i386-unknown-linux):
        RegAllocLinear.getStackSlotFor: out of stack slots, try -fregs-graph

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

cabal: Error: some packages failed to install:
Crypto-4.1.0 failed during the building phase. The exception was:
exit: ExitFailure 1

twice, so it seems to be reproducible. However, passing the flag -fregs-graph, it built without error (though compiling the SHA1Test Main took a long time, approximately two minutes).

[igloo]

Thanks for the report. Happily, this is a duplicate of #2424, and already fixed.