Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: hack (user goal)
rejecting: hack-2012.2.6, 2009.10.30, 2009.7.15, 2009.5.19, 2009.4.52,
2009.4.51, 2009.4.30, 2009.4.29, 2009.4.28, 2009.4.27 (global constraint
requires ==2009.4.26)
trying: hack-2009.4.26
trying: mps-2010.11.28 (dependency of hack-2009.4.26)
trying: template-haskell-2.9.0.0/installed-3af... (dependency of
mps-2010.11.28)
trying: parsec-3.1.9 (dependency of mps-2010.11.28)
trying: mtl-2.2.1 (dependency of parsec-3.1.9)
next goal: hyena (dependency of hack-2009.4.26)
rejecting: hyena-0.1.0.1 (conflict: template-haskell =>
containers==0.5.5.1/installed-23e..., hyena => containers>=0.3 && <0.4)
rejecting: hyena-0.1 (conflict: mtl==2.2.1, hyena => mtl>=1 && <1.2)
Backjump limit reached (change with --max-backjumps).