Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: BNFC (user goal)
rejecting: BNFC-2.8.1, BNFC-2.8, BNFC-2.7.1, BNFC-2.7.0.1, BNFC-2.7.0.0,
BNFC-2.6.0.3, BNFC-2.6.0.2, BNFC-2.6.0.1, BNFC-2.6.0.0, BNFC-2.5.0,
BNFC-2.4.2.1, BNFC-2.4.2.0, BNFC-2.4.1.2 (constraint from user target requires
==2.4.1.1)
trying: BNFC-2.4.1.1
trying: base-4.9.0.0/installed-4.9... (dependency of BNFC-2.4.1.1)
trying: process-1.4.2.0/installed-1.4... (dependency of BNFC-2.4.1.1)
next goal: haskell98 (dependency of BNFC-2.4.1.1)
rejecting: haskell98-2.0.0.3 (conflict: base==4.9.0.0/installed-4.9...,
haskell98 => base>=4.7 && <4.8)
rejecting: haskell98-2.0.0.2 (conflict: base==4.9.0.0/installed-4.9...,
haskell98 => base==4.6.*)
rejecting: haskell98-2.0.0.1, haskell98-2.0.0.0 (conflict: process =>
directory==1.2.6.2/installed-1.2..., haskell98 => directory>=1.1 && <1.2)
rejecting: haskell98-1.1.0.1, haskell98-1.1.0.0, haskell98-1.0.1.1 (conflict:
base==4.9.0.0/installed-4.9..., haskell98 => base>=3 && <4.6)
rejecting: haskell98-1.0.1.0 (conflict: base==4.9.0.0/installed-4.9...,
haskell98 => base<4.6)
rejecting: haskell98-1.0 (conflict: base==4.9.0.0/installed-4.9..., haskell98
=> base<4.3)
Dependency tree exhaustively searched.