Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: vacuum-cairo (user goal)
rejecting: vacuum-cairo-0.5, 0.4.1, 0.4, 0.3.1 (global constraint requires
==0.3)
trying: vacuum-cairo-0.3
trying: base-4.8.1.0/installed-4f7... (dependency of vacuum-cairo-0.3)
next goal: strict-concurrency (dependency of vacuum-cairo-0.3)
rejecting: strict-concurrency-0.2.4.1, 0.2.4 (conflict:
base==4.8.1.0/installed-4f7..., strict-concurrency => base>=4 && <4.6)
rejecting: strict-concurrency-0.2.3 (conflict: base==4.8.1.0/installed-4f7...,
strict-concurrency => base>=3 && <4.3)
rejecting: strict-concurrency-0.2.2, 0.2.1 (conflict:
base==4.8.1.0/installed-4f7..., strict-concurrency => base>=3 && <4)
rejecting: strict-concurrency-0.2, 0.1 (conflict:
base==4.8.1.0/installed-4f7..., strict-concurrency => base<4.3)
Dependency tree exhaustively searched.