Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] trying: zre-0.1.5.0 (user goal)
[__1] next goal: zeromq4-haskell (dependency of zre)
[__1] rejecting: zeromq4-haskell-0.8.0 (conflict: pkg-config package
libzmq(==4.0 || >4.0) && <5.0, not found in the pkg-config database)
[__1] rejecting: zeromq4-haskell-0.7.0 (conflict: zre =>
zeromq4-haskell^>=0.8)
[__1] skipping: zeromq4-haskell-0.6.7, zeromq4-haskell-0.6.6,
zeromq4-haskell-0.6.5, zeromq4-haskell-0.6.4, zeromq4-haskell-0.6.3,
zeromq4-haskell-0.6.2, zeromq4-haskell-0.6.1, zeromq4-haskell-0.6,
zeromq4-haskell-0.5.1, zeromq4-haskell-0.5, zeromq4-haskell-0.4.1,
zeromq4-haskell-0.4, zeromq4-haskell-0.3.2, zeromq4-haskell-0.3.1,
zeromq4-haskell-0.3, zeromq4-haskell-0.2, zeromq4-haskell-0.1 (has the same
characteristics that caused the previous version to fail: excluded by
constraint '^>=0.8' from 'zre')
[__1] fail (backjumping, conflict set: zeromq4-haskell, zre)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: zre, zeromq4-haskell