Resolving dependencies...
cabal: Could not resolve dependencies:
trying: async-2.1.1.1/installed-H3j... (dependency of shelly-1.7.0)
trying: ipython-kernel-0.9.0.1 (dependency of ihaskell-widgets-0.2.3.2)
next goal: zeromq4-haskell (dependency of ipython-kernel-0.9.0.1)
rejecting: zeromq4-haskell-0.7.0, zeromq4-haskell-0.6.7,
zeromq4-haskell-0.6.6, zeromq4-haskell-0.6.5, zeromq4-haskell-0.6.4 (conflict:
requires pkg-config package libzmq>=4.0 && <5.0, not found in the pkg-config
database)
rejecting: 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 (conflict:
async==2.1.1.1/installed-H3j..., zeromq4-haskell => async==2.0.*)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: zeromq4-haskell, async,
ipython-kernel, ihaskell, base, ihaskell-widgets