Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] next goal: libssh2 (user goal)
[__0] rejecting: libssh2-0.2.0.8 (conflict: pkg-config package libssh2==1.2.8
|| >1.2.8, not found in the pkg-config database)
[__0] rejecting: libssh2-0.2.0.7, libssh2-0.2.0.6, libssh2-0.2.0.5,
libssh2-0.2.0.4, libssh2-0.2.0.3, libssh2-0.2.0.2, libssh2-0.2.0.1,
libssh2-0.2, libssh2-0.1 (constraint from user target requires ==0.2.0.8)
[__0] fail (backjumping, conflict set: libssh2)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: libssh2