DO NOT MERGE: Flambda tests

[Stevendeo]

DO NOT MERGE

This branch can be used to test alt-ergo with flambda2. Adresses #906

[bclement-ocp]

I have tried to follow the instructions to setup a flambda option on the Marvin bot but I get the following error on the make _install step:

File "middle_end/flambda2/parser/flambda_parser.ml", line 5, characters 2-54:
5 |   CamlinternalMenhirLib.StaticVersion.require_20210419
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: Unbound value CamlinternalMenhirLib.StaticVersion.require_20210419
Hint: Did you mean require_20220210?

Is that something you encountered?

(Also paging @Gbury )

[bclement-ocp]

configure: Configuring Flambda backend version 5.1.1+jst

Ah! Probably I should not use the main branch :)

[bclement-ocp]

Well I tried with last-4.14 but I get a bunch of errors due to unused variables and magic potions. Will ask the flambda team.

[Gbury]

Well... the flambda2 repo is currently in the middle of a big backport to bring it up to date with the multicore release, and I think that as of now, installing flambda2 with opam is slightly broken. cc @lthls who might know of a way

[Stevendeo]

Is that something you encountered?

It may have been one of the issues I encountered, but iirc updating the menhir version was enough for this one. I had some issues with the compilation of dune actually...
Anyway, we said we would give up with flambda2, I'm trying with flambda