Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] next goal: palindromes (user goal)
[__0] rejecting: palindromes-1.0 (unsupported spec-version 3.12)
[__0] rejecting: palindromes-0.4, palindromes-0.3.2, palindromes-0.3.1,
palindromes-0.3, palindromes-0.2.2.2, palindromes-0.2.2.1, palindromes-0.2.2,
palindromes-0.2.1, palindromes-0.2, palindromes-0.1.1, palindromes-0.1
(constraint from user target requires ==1.0)
[__0] fail (backjumping, conflict set: palindromes)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: palindromes