id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
4360	compiler crash building hashed-storage 0.5.3	ganesh	simonpj	"{{{
ghc: panic! (the 'impossible' happened)
  (GHC version 7.0.0.20100924 for x86_64-unknown-linux):
        Expected one of wanted constraints (BUG)
}}}

This happens with {{{cabal install hashed-storage-0.5.3}}}, but that's a bit of a pain to reproduce as it depends on dataenc which needs a dependency bump. I cut it down to the attached file which just depends on mtl."	bug	closed	highest	7.0.1	Compiler	6.13	fixed		ganesh	Unknown/Multiple	Unknown/Multiple	Compile-time crash