Can no longer build hlint

[LeventErkok]

With the 0.8 release of ansi, I'm having issues while building sbv via cabal:

CallStack (from HasCallStack):
die', called at ./Distribution/Client/Install.hs:240:21 in main:Distribution.Client.Install
cabal: Could not resolve dependencies:
trying: ansi-terminal-0.8 (dependency of hlint-2.0.12)
trying: optparse-applicative-0.14.0.0 (dependency of tasty-golden-2.3.1.2)
next goal: ansi-wl-pprint (dependency of optparse-applicative-0.14.0.0)
rejecting: ansi-wl-pprint-0.6.8.1 (conflict: ansi-terminal==0.8,
ansi-wl-pprint => ansi-terminal>=0.4.0 && <0.8)
rejecting: ansi-wl-pprint-0.6.8, ansi-wl-pprint-0.6.7.3,
ansi-wl-pprint-0.6.7.2, ansi-wl-pprint-0.6.7.1, ansi-wl-pprint-0.6.7,
ansi-wl-pprint-0.6.6 (conflict: ansi-terminal==0.8, ansi-wl-pprint =>
ansi-terminal>=0.4.0 && <0.7)
rejecting: ansi-wl-pprint-0.6.4, ansi-wl-pprint-0.6.3, ansi-wl-pprint-0.6.2,
ansi-wl-pprint-0.6.1, ansi-wl-pprint-0.5.1, ansi-wl-pprint-0.5.0,
ansi-wl-pprint-0.4.0, ansi-wl-pprint-0.3.1, ansi-wl-pprint-0.3.0,
ansi-wl-pprint-0.2, ansi-wl-pprint-0.1 (conflict: optparse-applicative =>
ansi-wl-pprint>=0.6.6 && <0.7)
Backjump limit reached (currently 2000, change with --max-backjumps or try to
run with --reorder-goals).

Full logs here: https://travis-ci.org/LeventErkok/sbv/jobs/321887094

This is hard to interpret, but looking through the only change is a new release of ansi. Any help how I should go about fixing this would be great!

[UnkindPartition]

Well, ansi-wl-pprint puts an arbitrary upper bound on ansi-terminal, and for some reason Cabal doesn't get around to trying older versions of ansi-terminal.

Have you tried the flags suggested at the end of that output?

[LeventErkok]

No, I haven't. This is all CI builds, so I'm messing with flags is neither easy nor desirable. Perhaps we should ping ansi-wl-pprint folks to remove the upper bound?

[LeventErkok]

Just filed: ekmett/ansi-wl-pprint#17

[UnkindPartition]

Closing this — if anything, this looks like a cabal bug, and potentially fixed one. FWIW, I tried reproduce this on my machine but did not succeed.

[LeventErkok]

Adding --max-backjumps=-1 fixed the issue. Probably not worth digging further into it. Thanks!