Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] trying: xrefcheck-0.2.1 (user goal)
[__1] trying: roman-numerals-0.5.1.5 (dependency of xrefcheck)
[__2] trying: mtl-2.2.2/installed-2.2.2 (dependency of xrefcheck)
[__3] next goal: bytestring (dependency of xrefcheck)
[__3] rejecting: bytestring-0.11.3.1/installed-0.11.3.1 (conflict:
roman-numerals => bytestring>=0.9.1 && <0.11)
[__3] skipping: bytestring-0.11.3.1, bytestring-0.11.3.0, bytestring-0.11.2.0,
bytestring-0.11.1.0, bytestring-0.11.0.0 (has the same characteristics that
caused the previous version to fail: excluded by constraint '>=0.9.1 && <0.11'
from 'roman-numerals')
[__3] rejecting: bytestring-0.10.12.1 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.2 && <4.16)
[__3] rejecting: bytestring-0.10.12.0, bytestring-0.10.10.1,
bytestring-0.10.10.0 (conflict: mtl => base==4.16.3.0/installed-4.16.3.0,
bytestring => base>=4.2 && <4.15)
[__3] rejecting: bytestring-0.10.9.0 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.2 && <4.16)
[__3] rejecting: bytestring-0.10.8.2, bytestring-0.10.8.1 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.2 && <4.15)
[__3] rejecting: bytestring-0.10.8.0 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.8 && <4.15)
[__3] rejecting: bytestring-0.10.6.0 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.2 && <4.11)
[__3] rejecting: bytestring-0.10.4.1 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.2 && <4.15)
[__3] rejecting: bytestring-0.10.4.0 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.2 && <4.4 || >=4.5 &&
<4.15)
[__3] rejecting: bytestring-0.10.2.0, bytestring-0.10.0.2, bytestring-0.10.0.1
(conflict: mtl => base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.2
&& <4.15)
[__3] rejecting: bytestring-0.10.0.0 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4.4 && <4.15)
[__3] rejecting: bytestring-0.9.2.1 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4 && <4.11)
[__3] rejecting: bytestring-0.9.2.0 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4 && <4.6)
[__3] rejecting: bytestring-0.9.1.10, bytestring-0.9.1.9, bytestring-0.9.1.8,
bytestring-0.9.1.7, bytestring-0.9.1.6, bytestring-0.9.1.5 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4 && <4.4)
[__3] rejecting: bytestring-0.9.1.4 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring => base>=4 && <4.2)
[__3] rejecting: bytestring-0.9.1.3 (conflict: mtl =>
base==4.16.3.0/installed-4.16.3.0, bytestring +/-split-syb => base<4.2)
[__3] rejecting: bytestring-0.9.1.2, bytestring-0.9.1.1, bytestring-0.9.1.0
(conflict: mtl => base==4.16.3.0/installed-4.16.3.0, bytestring => base<4.2)
[__3] rejecting: bytestring-0.9.0.4 (conflict: roman-numerals =>
bytestring>=0.9.1 && <0.11)
[__3] skipping: bytestring-0.9.0.3, bytestring-0.9.0.2, bytestring-0.9.0.1,
bytestring-0.9 (has the same characteristics that caused the previous version
to fail: excluded by constraint '>=0.9.1 && <0.11' from 'roman-numerals')
[__3] fail (backjumping, conflict set: bytestring, mtl, roman-numerals,
xrefcheck)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: base, roman-numerals, mtl, xrefcheck,
bytestring
Try running with --minimize-conflict-set to improve the error message.