Resolving dependencies...
cabal: Could not resolve dependencies:
trying: prolog-graph-0.1.0.2 (user goal)
trying: graphviz-2999.17.0.2 (dependency of prolog-graph-0.1.0.2)
trying: transformers-0.3.0.0/installed-16a... (dependency of
graphviz-2999.17.0.2)
trying: temporary-1.2.0.3 (dependency of graphviz-2999.17.0.2)
trying: exceptions-0.8.0.2 (dependency of temporary-1.2.0.3)
trying: transformers-compat-0.4.0.4 (dependency of exceptions-0.8.0.2)
trying: transformers-compat-0.4.0.4:-two
rejecting: transformers-compat-0.4.0.4:-three (conflict:
transformers==0.3.0.0/installed-16a..., transformers-compat-0.4.0.4:three =>
transformers>=0.4.1 && <0.5)
rejecting: transformers-compat-0.4.0.4:+three (manual flag can only be changed
explicitly)
Backjump limit reached (change with --max-backjumps).