add --save-bfq-on-error flag for liquidhaskell and include it in CI

[kaf-lamed-beyt]

i'm not sure how to pass the --save-bfq-on-error through the LH plugin test pipeline like you (@facundominguez) did in the previous PR. the extraOpts in Build.hs goes to cabal build, not to individual test executables.

[kaf-lamed-beyt]

@facundominguez, can you take a look at this?

i'll follow up with the other PRs addressing points 2 and 3 in #2020 once this is clear.

[facundominguez]

Hello @kaf-lamed-beyt. Thanks for the PR!
Passing options to the Liquid Haskell plugin requires special GHC flags [link].

Probably, it should go in tests/tests.cabal.

[kaf-lamed-beyt]

oh alright, i'll check this out.

thank you, @facundominguez!

[kaf-lamed-beyt]

@facundominguez, let me know how it looks now.

[facundominguez]

Thanks @kaf-lamed-beyt.

I guess we don't want to pass this flag to tests that are expected to fail. They are in testsuite with names containing the neg infix, and there is the errors testsuite.

Perhaps we could use a common stanza for negative tests:

common ghc-options-for-negated-tests
    ghc-options: -fplugin-opt=LiquidHaskell:--save-bfq-on-error
...
executable errors
    import:           common-ghc-options, ghc-options-for-negated-tests
    ...
...

[kaf-lamed-beyt]

ah, i see. that's much better. lemme find the neg infixes.

[kaf-lamed-beyt]

@facundominguez, i've just updated it now. let me know how it looks. thank you.

[facundominguez]

Thanks @kaf-lamed-beyt! Something is amiss with the CI jobs. Otherwise, the changes look good to me.

[kaf-lamed-beyt]

hmmm... i think there's a merge conflict in liquid-fixpoint. i'll try attending to that and see if it resolves it.