Resolving dependencies... cabal: Could not resolve dependencies: next goal: yesod-bin (user goal) rejecting: yesod-bin-1.4.9.2, 1.4.9.1, 1.4.9, 1.4.8, 1.4.7.2, 1.4.7.1, 1.4.7, 1.4.6, 1.4.5.1, 1.4.5, 1.4.4, 1.4.3.11, 1.4.3.10, 1.4.3.9, 1.4.3.7, 1.4.3.6, 1.4.3.5, 1.4.3.4, 1.4.3.3, 1.4.3.2, 1.4.3.1, 1.4.3, 1.4.2, 1.4.1.2, 1.4.1.1, 1.4.1, 1.4.0.9, 1.4.0.8, 1.4.0.7, 1.4.0.6, 1.4.0.5, 1.4.0.4, 1.4.0.3, 1.4.0.2, 1.4.0.1, 1.4.0, 1.2.13, 1.2.12.8, 1.2.12.7, 1.2.12.6, 1.2.12.5, 1.2.12.4, 1.2.12.3, 1.2.12.2, 1.2.12.1, 1.2.12, 1.2.11, 1.2.10.3, 1.2.10.2, 1.2.10.1, 1.2.10, 1.2.9.4, 1.2.9.3, 1.2.9.2, 1.2.9.1, 1.2.9, 1.2.8.1, 1.2.8, 1.2.7.4, 1.2.7.3, 1.2.7.2, 1.2.7.1, 1.2.7, 1.2.6.1, 1.2.6, 1.2.5.8, 1.2.5.7, 1.2.5.6, 1.2.5.5, 1.2.5.4, 1.2.5.3, 1.2.5.2, 1.2.5.1, 1.2.5, 1.2.4.1, 1.2.4, 1.2.3.4, 1.2.3.3, 1.2.3.2, 1.2.3.1, 1.2.3, 1.2.2.1, 1.2.2, 1.2.1, 1.2.0.1 (global constraint requires ==1.2.0) trying: yesod-bin-1.2.0 trying: transformers-0.3.0.0/installed-16a... (dependency of yesod-bin-1.2.0) trying: project-template-0.2.0 (dependency of yesod-bin-1.2.0) trying: conduit-extra-1.1.9 (dependency of project-template-0.2.0) trying: transformers-base-0.4.4 (dependency of conduit-extra-1.1.9) trying: transformers-compat-0.4.0.4 (dependency of transformers-base-0.4.4) 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) Dependency tree exhaustively searched.