Resolving dependencies...
cabal: Could not resolve dependencies:
[__0] next goal: fswait (user goal)
[__0] rejecting: fswait-1.1.0 (constraint from user target requires ==1.0.0)
[__0] trying: fswait-1.0.0
[__1] next goal: turtle (dependency of fswait)
[__1] rejecting: turtle-1.5.22 (conflict: fswait => turtle>=1.2.8 && <1.3)
[__1] skipping: turtle-1.5.21, turtle-1.5.20, turtle-1.5.19, turtle-1.5.18,
turtle-1.5.17, turtle-1.5.16, turtle-1.5.15, turtle-1.5.14, turtle-1.5.13,
turtle-1.5.12, turtle-1.5.11, turtle-1.5.10, turtle-1.5.9, turtle-1.5.8,
turtle-1.5.7, turtle-1.5.6, turtle-1.5.5, turtle-1.5.4, turtle-1.5.3,
turtle-1.5.2, turtle-1.5.1, turtle-1.5.0, turtle-1.4.6, turtle-1.4.5,
turtle-1.4.4, turtle-1.4.3, turtle-1.4.2, turtle-1.4.1, turtle-1.4.0,
turtle-1.3.6, turtle-1.3.5, turtle-1.3.4, turtle-1.3.3, turtle-1.3.2,
turtle-1.3.1, turtle-1.3.0 (has the same characteristics that caused the
previous version to fail: excluded by constraint '>=1.2.8 && <1.3' from
'fswait')
[__1] trying: turtle-1.2.8
[__2] next goal: unix (dependency of turtle)
[__2] rejecting: unix-2.7.2.2/installed-2.7.2.2 (conflict: turtle => time<1.7,
unix => time==1.9.3/installed-1.9.3)
[__2] trying: unix-2.7.2.2
[__3] trying: bytestring-0.10.10.0/installed-0.10.10.0 (dependency of unix)
[__4] trying: deepseq-1.4.4.0/installed-1.4.4.0 (dependency of bytestring)
[__5] trying: array-0.5.4.0/installed-0.5.4.0 (dependency of deepseq)
[__6] next goal: time (dependency of turtle)
[__6] rejecting: time-1.9.3/installed-1.9.3 (conflict: turtle => time<1.7)
[__6] skipping: time-1.11.1.2, time-1.11.1.1, time-1.11.1, time-1.11,
time-1.10, time-1.9.3, time-1.9.2, time-1.9.1, time-1.9, time-1.8.0.4,
time-1.8.0.3, time-1.8.0.2, time-1.8.0.1, time-1.8, time-1.7.0.1, time-1.7
(has the same characteristics that caused the previous version to fail:
excluded by constraint '<1.7' from 'turtle')
[__6] rejecting: time-1.6.0.1 (conflict: bytestring =>
base==4.14.1.0/installed-4.14.1.0, time => base>=4.7 && <4.13)
[__6] rejecting: time-1.6 (conflict: bytestring =>
base==4.14.1.0/installed-4.14.1.0, time => base>=4.8 && <4.13)
[__6] rejecting: time-1.5.0.1 (conflict: bytestring =>
base==4.14.1.0/installed-4.14.1.0, time => base>=4.4 && <4.13)
[__6] rejecting: time-1.5, time-1.4.2, time-1.4.1 (conflict: bytestring =>
deepseq==1.4.4.0/installed-1.4.4.0, time => deepseq>=1.1 && <1.4)
[__6] rejecting: time-1.4.0.2 (conflict: bytestring =>
base==4.14.1.0/installed-4.14.1.0, time => base>=4.4 && <4.7)
[__6] rejecting: time-1.4.0.1, time-1.4, time-1.3, time-1.2.0.5, time-1.2.0.4,
time-1.2.0.3, time-1.2.0.2, time-1.2.0.1 (conflict: bytestring =>
base==4.14.1.0/installed-4.14.1.0, time => base>=4 && <4.7)
[__6] rejecting: time-1.2 (conflict: bytestring =>
base==4.14.1.0/installed-4.14.1.0, time => base(>=4 && <4.7) && <0)
[__6] rejecting: time-1.1.4 (conflict: unix => time>=1.2 && <1.12)
[__6] skipping: time-1.1.3, time-1.1.2.4, time-1.1.2.3, time-1.1.2.2,
time-1.1.2.1, time-1.1.2.0, time-1.0 (has the same characteristics that caused
the previous version to fail: excluded by constraint '>=1.2 && <1.12' from
'unix')
[__6] fail (backjumping, conflict set: bytestring, time, turtle, unix)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: base, turtle, time, deepseq, fswait,
array, bytestring, unix
Try running with --minimize-conflict-set to improve the error message.