Ticket #5684 (closed bug: fixed)
ghc: panic! (the 'impossible' happened) (ghc 7.2.2)
I seem to have found an "impossible" bug, and I am reporting it here as instructed.
The bug can be reliably reproduced with gcc-7.2.2. I can reproduce this bug with both the binaries from the generic 64-bit linux distribution ghc-7.2.2-x86_64-unknown-linux.tar.bz2, and the generic 32-bit linux distribution ghc-7.2.2-i386-unknown-linux.tar.bz2 (these were the only two I tried).
Unfortunately, I can't publicly send the source code, because it is part of a confidential project. However, if this bug is not yet known/fixed, I can probably produce a minimal and "sanitized" example.
Here is what I get:
ghc -o qcs Main.hs [ 9 of 10] Compiling BWT ( BWT.hs, BWT.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.2.2 for i386-unknown-linux): Unexpected given! Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug make: *** [qcs] Error 1
Please let me know how I can proceed to collect more information on this bug! Thanks, -- Peter