Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: poppler (user goal)
rejecting: poppler-0.14.1, poppler-0.14.0, poppler-0.14, poppler-0.13.1,
poppler-0.13, poppler-0.12.3, poppler-0.12.2.2, poppler-0.12.2.1,
poppler-0.12.2, poppler-0.12.1 (constraint from user target requires ==0.12.0)
trying: poppler-0.12.0
next goal: tk (dependency of poppler-0.12.0)
Dependency tree exhaustively searched.