From: Mozhgan kabiri
Hi,
I am trying to install Criterion package, but I keep getting an error and I can't figure it out why it is like this !!
mozhgan@Mozhgan-KCh:~$ cabal install Criterion Resolving dependencies... Configuring vector-algorithms-0.3... Preprocessing library vector-algorithms-0.3... Building vector-algorithms-0.3... ...
[8 of 9] Compiling Data.Vector.Algorithms.Intro ( Data/Vector/Algorithms/Intro.hs, dist/build/Data/Vector/Algorithms/Intro.o ) ghc: panic! (the 'impossible' happened) (GHC version 6.10.4 for i386-unknown-linux): idInfo co{v a9WB} [tv]
This is definitely a bug in GHC, most likely related to type families and fixed in GHC-6.12.x If you can upgrade to ghc-6.12.1, that should solve this problem. If you need to remain on ghc-6.10.4, try installing an older version of criterion. You can do this with 'cabal install criterion-0.4.1.0' Criterion-0.5 is the first version to depend upon vector-algorithms, so any previous version has a chance of working. John