Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] trying: hspec-api-2.11.16 (user goal)
[__1] next goal: hspec-core (dependency of hspec-api)
[__1] rejecting: hspec-core-2.11.15 (conflict: hspec-api =>
hspec-core==2.11.16)
[__1] skipping: hspec-core-2.11.14, hspec-core-2.11.13, hspec-core-2.11.12,
hspec-core-2.11.11, hspec-core-2.11.10, hspec-core-2.11.9, hspec-core-2.11.8,
hspec-core-2.11.7, hspec-core-2.11.6, hspec-core-2.11.5, hspec-core-2.11.4,
hspec-core-2.11.3, hspec-core-2.11.2, hspec-core-2.11.1, hspec-core-2.11.0.1,
hspec-core-2.11.0, hspec-core-2.10.10, hspec-core-2.10.9, hspec-core-2.10.8,
hspec-core-2.10.7, hspec-core-2.10.6, hspec-core-2.10.5, hspec-core-2.10.4,
hspec-core-2.10.3, hspec-core-2.10.2, hspec-core-2.10.1, hspec-core-2.10.0.1,
hspec-core-2.10.0, hspec-core-2.9.7, hspec-core-2.9.6, hspec-core-2.9.5,
hspec-core-2.9.4, hspec-core-2.9.3, hspec-core-2.9.2, hspec-core-2.9.1,
hspec-core-2.9.0, hspec-core-2.8.5, hspec-core-2.8.4, hspec-core-2.8.3,
hspec-core-2.8.2, hspec-core-2.8.1, hspec-core-2.8.0, hspec-core-2.7.10,
hspec-core-2.7.9, hspec-core-2.7.8, hspec-core-2.7.7, hspec-core-2.7.6,
hspec-core-2.7.5, hspec-core-2.7.4, hspec-core-2.7.3, hspec-core-2.7.2,
hspec-core-2.7.1, hspec-core-2.7.0, hspec-core-2.6.1, hspec-core-2.6.0,
hspec-core-2.5.9, hspec-core-2.5.8, hspec-core-2.5.7, hspec-core-2.5.6,
hspec-core-2.5.5, hspec-core-2.5.4, hspec-core-2.5.3, hspec-core-2.5.2,
hspec-core-2.5.1, hspec-core-2.5.0, hspec-core-2.4.8, hspec-core-2.4.7,
hspec-core-2.4.6, hspec-core-2.4.5, hspec-core-2.4.4, hspec-core-2.4.3,
hspec-core-2.4.2, hspec-core-2.4.1, hspec-core-2.4.0, hspec-core-2.3.2,
hspec-core-2.3.1, hspec-core-2.3.0, hspec-core-2.2.4, hspec-core-2.2.3,
hspec-core-2.2.2, hspec-core-2.2.1, hspec-core-2.2.0, hspec-core-2.1.10,
hspec-core-2.1.9, hspec-core-2.1.8, hspec-core-2.1.7, hspec-core-2.1.6,
hspec-core-2.1.5, hspec-core-2.1.4, hspec-core-2.1.3, hspec-core-2.1.2,
hspec-core-2.1.1, hspec-core-2.1.0, hspec-core-2.0.2, hspec-core-2.0.1,
hspec-core-2.0.0 (has the same characteristics that caused the previous
version to fail: excluded by constraint '==2.11.16' from 'hspec-api')
[__1] fail (backjumping, conflict set: hspec-api, hspec-core)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: hspec-api, hspec-core