Resolving dependencies... cabal: Could not resolve dependencies: trying: bibdb-0.5.2 (user goal) trying: transformers-0.5.2.0/installed-0.5... (dependency of bibdb-0.5.2) next goal: optparse-applicative (dependency of bibdb-0.5.2) rejecting: optparse-applicative-0.13.0.0, optparse-applicative-0.12.1.0 (conflict: bibdb => optparse-applicative==0.12.0.*) rejecting: optparse-applicative-0.12.0.0 (conflict: transformers==0.5.2.0/installed-0.5..., optparse-applicative => transformers>=0.2 && <0.5) rejecting: optparse-applicative-0.11.0.2, optparse-applicative-0.11.0.1, optparse-applicative-0.11.0, optparse-applicative-0.10.0, optparse-applicative-0.9.1.1, optparse-applicative-0.9.1, optparse-applicative-0.9.0, optparse-applicative-0.8.1, optparse-applicative-0.8.0.1, optparse-applicative-0.8.0, optparse-applicative-0.7.0.2, optparse-applicative-0.7.0.1, optparse-applicative-0.7.0, optparse-applicative-0.6.0, optparse-applicative-0.5.2.1, optparse-applicative-0.5.2, optparse-applicative-0.5.1, optparse-applicative-0.5.0, optparse-applicative-0.4.3, optparse-applicative-0.4.2, optparse-applicative-0.4.1, optparse-applicative-0.4.0, optparse-applicative-0.3.2, optparse-applicative-0.3.1, optparse-applicative-0.3.0, optparse-applicative-0.2.0, optparse-applicative-0.1.1, optparse-applicative-0.1.0, optparse-applicative-0.0.1 (conflict: bibdb => optparse-applicative==0.12.0.*) Dependency tree exhaustively searched.