Resolving dependencies...
cabal: Could not resolve dependencies:
trying: happstack-plugins-7.0.2 (user goal)
trying: base-4.9.0.0/installed-4.9... (dependency of happstack-plugins-7.0.2)
next goal: template-haskell (dependency of happstack-plugins-7.0.2)
rejecting: template-haskell-2.11.0.0/installed-2.1...,
template-haskell-2.11.0.0, template-haskell-2.10.0.0,
template-haskell-2.9.0.0, template-haskell-2.8.0.0 (conflict:
happstack-plugins => template-haskell>=2.6 && <2.8)
rejecting: template-haskell-2.7.0.0 (conflict: base==4.9.0.0/installed-4.9...,
template-haskell => base==4.5.*)
rejecting: template-haskell-2.6.0.0 (conflict: base==4.9.0.0/installed-4.9...,
template-haskell => base==4.4.*)
rejecting: template-haskell-2.5.0.0, template-haskell-2.4.0.1,
template-haskell-2.4.0.0, template-haskell-2.3.0.1, template-haskell-2.3.0.0,
template-haskell-2.2.0.0 (conflict: happstack-plugins => template-haskell>=2.6
&& <2.8)
Dependency tree exhaustively searched.