Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] next goal: gsasl (user goal)
[__0] rejecting: gsasl-0.4.0 (conflict: pkg-config package libgsasl>=1.1, not
found in the pkg-config database)
[__0] rejecting: gsasl-0.3.7, gsasl-0.3.6, gsasl-0.3.5, gsasl-0.3.4,
gsasl-0.3.3, gsasl-0.3.2, gsasl-0.3.1, gsasl-0.3, gsasl-0.2, gsasl-0.1
(constraint from user target requires ==0.4.0)
[__0] fail (backjumping, conflict set: gsasl)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: gsasl