Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: boomslang (user goal)
rejecting: boomslang-0.0.4, 0.0.3 (global constraint requires ==0.0.2)
trying: boomslang-0.0.2
trying: base-4.8.1.0/installed-4f7... (dependency of boomslang-0.0.2)
next goal: mtl (dependency of boomslang-0.0.2)
rejecting: mtl-2.2.1, 2.2.0.1, 2.2, 2.1.3.1, 2.1.2, 2.1.1, 2.1, 2.0.1.1,
2.0.1.0, 2.0.0.0 (conflict: boomslang => mtl==1.*)
rejecting: mtl-1.1.1.1, 1.1.1.0 (conflict: base==4.8.1.0/installed-4f7..., mtl
=> base<4.6)
rejecting: mtl-1.1.0.2, 1.1.0.1, 1.1.0.0, 1.0 (conflict:
base==4.8.1.0/installed-4f7..., mtl => base<4.3)
Dependency tree exhaustively searched.