Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: DAV (user goal)
rejecting: DAV-1.2, 1.1, 1.0.7, 1.0.6, 1.0.5, 1.0.4, 1.0.3, 1.0.2, 1.0.1, 1.0,
0.8, 0.7, 0.6.2, 0.6.1, 0.6, 0.5.1, 0.5, 0.4.1, 0.4, 0.3.1, 0.3, 0.2, 0.1,
0.0.1 (global constraint requires ==0.0)
trying: DAV-0.0
next goal: base (dependency of DAV-0.0)
rejecting: base-4.8.1.0/installed-4f7... (conflict: DAV => base==4.5.*)
rejecting: base-4.8.1.0, 4.8.0.0, 4.7.0.2, 4.7.0.1, 4.7.0.0, 4.6.0.1, 4.6.0.0,
4.5.1.0, 4.5.0.0, 4.4.1.0, 4.4.0.0, 4.3.1.0, 4.3.0.0, 4.2.0.2, 4.2.0.1,
4.2.0.0, 4.1.0.0, 4.0.0.0, 3.0.3.2, 3.0.3.1 (global constraint requires
installed instance)
Dependency tree exhaustively searched.