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: parsec-3.1.9 (dependency of mps-2010.11.28) trying: text-1.2.1.3 (dependency of parsec-3.1.9) trying: binary-0.7.5.0/installed-072... (dependency of text-1.2.1.3) 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: binary => containers==0.5.6.2/installed-2de..., 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).