Resolving dependencies...
cabal: Could not resolve dependencies:
trying: Befunge93-0.1 (user goal)
trying: base-4.9.0.0/installed-4.9... (dependency of Befunge93-0.1)
next goal: mtl (dependency of Befunge93-0.1)
rejecting: mtl-2.2.1, mtl-2.2.0.1, mtl-2.2, mtl-2.1.3.1, mtl-2.1.2, mtl-2.1.1,
mtl-2.1, mtl-2.0.1.1, mtl-2.0.1.0, mtl-2.0.0.0 (conflict: Befunge93 => mtl<2)
rejecting: mtl-1.1.1.1, mtl-1.1.1.0 (conflict: base==4.9.0.0/installed-4.9...,
mtl => base<4.6)
rejecting: mtl-1.1.0.2, mtl-1.1.0.1, mtl-1.1.0.0, mtl-1.0 (conflict:
base==4.9.0.0/installed-4.9..., mtl => base<4.3)
Dependency tree exhaustively searched.