Resolving dependencies...
cabal: Could not resolve dependencies:
next goal: scyther-proof (user goal)
rejecting: scyther-proof-0.10.0.1, 0.10.0.0, 0.8.0.0, 0.6.0.0, 0.5.0.0,
0.4.1.0 (global constraint requires ==0.4.0)
trying: scyther-proof-0.4.0
trying: base-4.8.1.0/installed-4f7... (dependency of scyther-proof-0.4.0)
next goal: tagsoup (dependency of scyther-proof-0.4.0)
rejecting: tagsoup-0.13.5, 0.13.4, 0.13.3, 0.13.2, 0.13.1, 0.13 (conflict:
scyther-proof => tagsoup==0.12.*)
rejecting: tagsoup-0.12.8, 0.12.7, 0.12.6, 0.12.5, 0.12.4, 0.12.3 (conflict:
base==4.8.1.0/installed-4f7..., tagsoup => base>=4 && <4.8)
rejecting: tagsoup-0.12.2, 0.12.1, 0.12 (conflict:
base==4.8.1.0/installed-4f7..., tagsoup => base>=4 && <4.4)
rejecting: tagsoup-0.11.1, 0.11, 0.10.1, 0.10, 0.9, 0.8, 0.6, 0.4, 0.1
(conflict: scyther-proof => tagsoup==0.12.*)
Dependency tree exhaustively searched.