Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: darcs-beta (user goal)
rejecting: darcs-beta-2.7.99.2, 2.7.99.1, 2.7.98.3, 2.7.98.2, 2.7.98.1,
2.4.99.1, 2.4.98.5, 2.4.98.4 (global constraint requires ==2.4.98.3)
trying: darcs-beta-2.4.98.3
trying: base-4.8.1.0/installed-4f7... (dependency of darcs-beta-2.4.98.3)
next goal: unix (dependency of darcs-beta-2.4.98.3)
rejecting: unix-2.7.1.0/installed-643..., 2.7.1.0, 2.7.0.1, 2.7.0.0, 2.6.0.1,
2.6.0.0, 2.5.1.1, 2.5.1.0, 2.5.0.0 (conflict: darcs-beta => unix>=1.0 && <2.5)
rejecting: unix-2.4.2.0, 2.4.1.0 (conflict: base==4.8.1.0/installed-4f7...,
unix => base>=4.2 && <4.4)
rejecting: unix-2.4.0.2, 2.4.0.1 (conflict: base==4.8.1.0/installed-4f7...,
unix => base>=4.2 && <4.3)
rejecting: unix-2.4.0.0 (conflict: base==4.8.1.0/installed-4f7..., unix =>
base>=4.1 && <4.3)
rejecting: unix-2.3.2.0, 2.3.1.0, 2.3.0.0, 2.2.0.0, 2.0 (conflict:
base==4.8.1.0/installed-4f7..., unix => base<4.3)
Dependency tree exhaustively searched.