Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: happstack-clientsession (user goal)
rejecting: happstack-clientsession-7.3.0, 7.2.7, 7.2.6, 7.2.5, 7.2.4, 7.2.3,
7.2.2 (global constraint requires ==7.2.1)
trying: happstack-clientsession-7.2.1
trying: base-4.7.0.1/installed-e4b... (dependency of
happstack-clientsession-7.2.1)
trying: transformers-base-0.4.4 (dependency of happstack-clientsession-7.2.1)
next goal: transformers (dependency of transformers-base-0.4.4)
rejecting: transformers-0.3.0.0/installed-16a... (conflict:
transformers-compat-0.4.0.4:three => transformers>=0.4.1 && <0.5)
trying: transformers-0.4.3.0
next goal: mtl (dependency of happstack-clientsession-7.2.1)
rejecting: mtl-2.2.1, 2.2.0.1, 2.2 (conflict: happstack-clientsession =>
mtl>=2.0 && <2.2)
rejecting: mtl-2.1.3.1, 2.1.2 (conflict: transformers==0.4.3.0, mtl =>
transformers==0.3.*)
rejecting: mtl-2.1.1, 2.1 (conflict: base==4.7.0.1/installed-e4b..., mtl =>
base<4.6)
rejecting: mtl-2.0.1.1 (conflict: transformers==0.4.3.0, mtl =>
transformers==0.2.*)
rejecting: mtl-2.0.1.0, 2.0.0.0 (conflict: base==4.7.0.1/installed-e4b..., mtl
=> base<4.6)
rejecting: mtl-1.1.1.1, 1.1.1.0, 1.1.0.2, 1.1.0.1, 1.1.0.0, 1.0 (conflict:
happstack-clientsession => mtl>=2.0 && <2.2)
Dependency tree exhaustively searched.