Resolving dependencies...
cabal: Could not resolve dependencies:
trying: hfd-0.0.2 (user goal)
trying: mtl-2.2.1 (dependency of MissingH-1.4.0.1)
next goal: transformers (dependency of hfd-0.0.2)
rejecting: transformers-0.5.2.0/installed-0.5..., transformers-0.5.2.0,
transformers-0.5.1.0, transformers-0.5.0.1, transformers-0.5.0.0,
transformers-0.4.3.0, transformers-0.4.2.0, transformers-0.4.1.0,
transformers-0.3.0.0 (conflict: hfd => transformers<0.3.0.0)
rejecting: transformers-0.2.2.1, transformers-0.2.1.0, transformers-0.2.0.0,
transformers-0.1.4.0, transformers-0.1.3.0, transformers-0.1.1.0,
transformers-0.1.0.1, transformers-0.0.1.0, transformers-0.0.0.0 (conflict:
mtl => transformers>=0.4 && <0.6)
rejecting: transformers-0.5.0.2, transformers-0.4.0.0 (conflict: hfd =>
transformers<0.3.0.0)
rejecting: transformers-0.2.2.0, transformers-0.1.0.0 (conflict: mtl =>
transformers>=0.4 && <0.6)
Backjump limit reached (currently 2000, change with --max-backjumps or try to
run with --reorder-goals).