[darcs-users] Dueling ghc versions

[Michael G Schwern]

Pugs (prototype Perl 6 compiler written in Haskell) now requires GHC 6.4.
So I upgraded ghc from 6.2 to 6.4.  darcs-unstable yelps.

ghc -I/sw/include -cpp  -package parsec -package unix -O -funbox-strict-fields -I/sw/include -Wall -Werror -package util -I. -DHAVE_CURSES -DHAVE_CURL -c Lock.lhs

Lock.lhs:54:0:
    Failed to load interface for `AtExit':
        Bad interface file: ./AtExit.hi
            mismatched interface file versions: expected 6040, found 6020
make: *** [Lock.o] Error 1

Don't know if this is expected or if there's anything darcs can do about it 
but it sure makes life difficult to have to keep two versions of ghc around.