Resolving dependencies... Error: cabal: Could not resolve dependencies: [__0] trying: exploring-interpreters-1.5.0.0 (user goal) [__1] next goal: haskeline (dependency of exploring-interpreters) [__1] rejecting: haskeline-0.8.2.1/installed-0.8.2.1 (conflict: exploring-interpreters => haskeline==0.8.2) [__1] skipping: haskeline-0.8.2.1 (has the same characteristics that caused the previous version to fail: excluded by constraint '==0.8.2' from 'exploring-interpreters') [__1] trying: haskeline-0.8.2 [__2] next goal: base (dependency of exploring-interpreters) [__2] rejecting: base-4.18.1.0/installed-4.18.1.0 (conflict: haskeline => base>=4.9 && <4.18) [__2] skipping: base-4.19.0.0, base-4.18.2.0, base-4.18.1.0, base-4.18.0.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=4.9 && <4.18' from 'haskeline') [__2] rejecting: base-4.17.2.1, base-4.17.2.0, base-4.17.1.0, base-4.17.0.0, base-4.16.4.0, base-4.16.3.0, base-4.16.2.0, base-4.16.1.0, base-4.16.0.0, base-4.15.1.0, base-4.15.0.0, base-4.14.3.0, base-4.14.2.0, base-4.14.1.0, base-4.14.0.0, base-4.13.0.0, base-4.12.0.0, base-4.11.1.0, base-4.11.0.0, base-4.10.1.0, base-4.10.0.0, base-4.9.1.0, base-4.9.0.0, base-4.8.2.0, base-4.8.1.0, base-4.8.0.0, base-4.7.0.2, base-4.7.0.1, base-4.7.0.0, base-4.6.0.1, base-4.6.0.0, base-4.5.1.0, base-4.5.0.0, base-4.4.1.0, base-4.4.0.0, base-4.3.1.0, base-4.3.0.0, base-4.2.0.2, base-4.2.0.1, base-4.2.0.0, base-4.1.0.0, base-4.0.0.0, base-3.0.3.2, base-3.0.3.1 (constraint from non-upgradeable package requires installed instance) [__2] fail (backjumping, conflict set: base, exploring-interpreters, haskeline) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: base, haskeline, exploring-interpreters