Resolving dependencies...
Error: cabal: Could not resolve dependencies:
[__0] trying: servant-util-0.4 (user goal)
[__1] trying: text-format-0.3.2 (dependency of servant-util)
[__2] next goal: integer-gmp (dependency of text-format)
[__2] rejecting: integer-gmp-1.1/installed-1.1 (conflict: text-format =>
base>=4.3 && <4.15, integer-gmp => base==4.16.3.0/installed-4.16.3.0)
[__2] rejecting: integer-gmp-1.1, integer-gmp-1.0.3.0, integer-gmp-1.0.2.0,
integer-gmp-1.0.1.0, integer-gmp-1.0.0.1, integer-gmp-1.0.0.0,
integer-gmp-0.5.1.0 (constraint from non-upgradeable package requires
installed instance)
[__2] fail (backjumping, conflict set: integer-gmp, text-format)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: base, text-format, integer-gmp,
servant-util
Try running with --minimize-conflict-set to improve the error message.