Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: alex (user goal)
rejecting: alex-3.1.4, 3.1.3, 3.1.2, 3.1.1, 3.1.0, 3.0.5, 3.0.4, 3.0.3, 3.0.2,
3.0.1, 3.0, 2.3.5, 2.3.4, 2.3.3, 2.3.2 (global constraint requires ==2.3.1)
trying: alex-2.3.1
trying: base-4.7.0.1/installed-e4b... (dependency of alex-2.3.1)
rejecting: alex-2.3.1:+small_base (conflict: base==4.7.0.1/installed-e4b...,
alex-2.3.1:small_base => base>=2.1 && <4.4)
rejecting: alex-2.3.1:-small_base (conflict: base==4.7.0.1/installed-e4b...,
alex-2.3.1:small_base => base>=1.0 && <2.1)
Dependency tree exhaustively searched.