Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] trying: registry-messagepack-0.3.0.1 (user goal)
[__1] next goal: msgpack (dependency of registry-messagepack)
[__1] rejecting: msgpack-1.0.1.0 (conflict: registry-messagepack =>
msgpack>=1.2 && <2)
[__1] skipping: msgpack-1.0.0, msgpack-0.7.2.5, msgpack-0.7.1.5,
msgpack-0.7.1.4, msgpack-0.7.1.3, msgpack-0.7.1.2, msgpack-0.7.1.1,
msgpack-0.7.1, msgpack-0.7.0, msgpack-0.6.4, msgpack-0.6.3, msgpack-0.6.2,
msgpack-0.6.1.3, msgpack-0.6.1.2, msgpack-0.6.1.1, msgpack-0.6.1,
msgpack-0.6.0.1, msgpack-0.6.0.0, msgpack-0.5.0.0, msgpack-0.4.0.1,
msgpack-0.4.0, msgpack-0.3.1.1, msgpack-0.3.1, msgpack-0.3.0, msgpack-0.2.2,
msgpack-0.2.0, msgpack-0.1.0 (has the same characteristics that caused the
previous version to fail: excluded by constraint '>=1.2 && <2' from
'registry-messagepack')
[__1] fail (backjumping, conflict set: msgpack, registry-messagepack)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: registry-messagepack, msgpack