Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: cassy (user goal)
rejecting: cassy-0.7.1, 0.6, 0.5.2, 0.5.1.0, 0.4.0.1, 0.4, 0.3.2, 0.2.0.3,
0.2.0.2 (global constraint requires ==0.2.0.1)
trying: cassy-0.2.0.1
trying: aeson-0.10.0.0 (dependency of cassy-0.2.0.1)
next goal: attoparsec (dependency of cassy-0.2.0.1)
rejecting: attoparsec-0.13.0.1, 0.13.0.0, 0.12.1.6, 0.12.1.5, 0.12.1.4,
0.12.1.3, 0.12.1.2, 0.12.1.1, 0.12.1.0, 0.12.0.0, 0.11.3.4, 0.11.3.3,
0.11.3.2, 0.11.3.1, 0.11.3.0, 0.11.2.1, 0.11.1.0 (conflict: cassy =>
attoparsec>=0.10 && <0.11)
rejecting: attoparsec-0.10.4.0, 0.10.3.0, 0.10.2.0, 0.10.1.1, 0.10.1.0,
0.10.0.3, 0.10.0.2, 0.10.0.1, 0.10.0.0 (conflict: aeson =>
attoparsec>=0.13.0.1)
rejecting: attoparsec-0.9.1.2, 0.9.1.1, 0.9.0.0, 0.8.6.1, 0.8.6.0, 0.8.5.3,
0.8.5.2, 0.8.5.1, 0.8.5.0, 0.8.4.0, 0.8.3.0, 0.8.2.0, 0.8.1.1, 0.8.1.0,
0.8.0.2, 0.8.0.1, 0.8.0.0, 0.7.2, 0.7.1, 0.6, 0.5.1, 0.5, 0.4 (conflict: cassy
=> attoparsec>=0.10 && <0.11)
Backjump limit reached (change with --max-backjumps).