Resolving dependencies... cabal: Could not resolve dependencies: next goal: yesod-core (user goal) rejecting: yesod-core-1.4.30, yesod-core-1.4.29, yesod-core-1.4.28, yesod-core-1.4.27, yesod-core-1.4.26, yesod-core-1.4.25, yesod-core-1.4.24, yesod-core-1.4.23.1, yesod-core-1.4.23, yesod-core-1.4.22, yesod-core-1.4.21, yesod-core-1.4.20.2, yesod-core-1.4.20.1, yesod-core-1.4.20, yesod-core-1.4.19, yesod-core-1.4.18.2, yesod-core-1.4.18.1, yesod-core-1.4.18, yesod-core-1.4.17, yesod-core-1.4.16, yesod-core-1.4.15.1, yesod-core-1.4.15, yesod-core-1.4.14, yesod-core-1.4.13, yesod-core-1.4.12, yesod-core-1.4.11.1, yesod-core-1.4.11, yesod-core-1.4.10, yesod-core-1.4.9.1, yesod-core-1.4.9, yesod-core-1.4.8.3, yesod-core-1.4.8.2, yesod-core-1.4.8.1, yesod-core-1.4.8, yesod-core-1.4.7.3, yesod-core-1.4.7.2, yesod-core-1.4.7.1, yesod-core-1.4.7, yesod-core-1.4.6.2, yesod-core-1.4.6.1, yesod-core-1.4.6, yesod-core-1.4.5, yesod-core-1.4.4.5, yesod-core-1.4.4.4, yesod-core-1.4.4.3, yesod-core-1.4.4.2, yesod-core-1.4.4.1, yesod-core-1.4.4, yesod-core-1.4.3.1, yesod-core-1.4.3, yesod-core-1.4.2, yesod-core-1.4.1.1, yesod-core-1.4.1, yesod-core-1.4.0.2, yesod-core-1.4.0.1, yesod-core-1.4.0, yesod-core-1.2.20.1, yesod-core-1.2.20, yesod-core-1.2.19.2, yesod-core-1.2.19.1, yesod-core-1.2.19, yesod-core-1.2.18, yesod-core-1.2.17, yesod-core-1.2.16.1, yesod-core-1.2.16, yesod-core-1.2.15.2, yesod-core-1.2.15.1, yesod-core-1.2.15, yesod-core-1.2.14, yesod-core-1.2.13.1 (constraint from user target requires ==1.2.13) trying: yesod-core-1.2.13 trying: base-4.9.0.0/installed-4.9... (dependency of yesod-core-1.2.13) trying: primitive-0.6.2.0 (dependency of conduit-extra-1.1.15) next goal: vector (dependency of yesod-core-1.2.13) rejecting: vector-0.11.0.0 (conflict: yesod-core => vector>=0.9 && <0.11) rejecting: vector-0.10.12.3 (conflict: primitive==0.6.2.0, vector => primitive>=0.5.0.1 && <0.6.2) rejecting: vector-0.10.12.2, vector-0.10.12.1, vector-0.10.11.0, vector-0.10.10.0, vector-0.10.9.2, vector-0.10.9.1, vector-0.10.9.0 (conflict: primitive==0.6.2.0, vector => primitive>=0.5.0.1 && <0.6) rejecting: vector-0.10.0.1, vector-0.10 (conflict: base==4.9.0.0/installed-4.9..., vector => base>=4 && <4.7) rejecting: vector-0.9.1, vector-0.9 (conflict: primitive==0.6.2.0, vector => primitive>=0.4.0.1 && <0.5) rejecting: vector-0.8, vector-0.7.1, vector-0.7.0.1, vector-0.7, vector-0.6.0.2, vector-0.6.0.1, vector-0.6, vector-0.5, vector-0.4.2, vector-0.4.1, vector-0.4, vector-0.3.1, vector-0.3, vector-0.2, vector-0.1 (conflict: yesod-core => vector>=0.9 && <0.11) rejecting: vector-0.10.12.0, vector-0.10.9.3 (conflict: primitive==0.6.2.0, vector => primitive>=0.5.0.1 && <0.6) Backjump limit reached (currently 2000, change with --max-backjumps or try to run with --reorder-goals).