Undefined external when importing Coq library

[ejgallego]

Dear @thierry-martinez ,

with ocaml-in-python master, OCaml 4.14, and Coq 8.19 installed from opam, I get:

>>> import ocaml                              # That works fine
>>> ocaml.require("coq-core.clib")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: Dynlink.Error (Dynlink.Cannot_open_dll "Dynlink.Error (Dynlink.Cannot_open_dll \"Failure(\\\"/home/egallego/research/coq-lsp/_build/install/default/lib/coq-core/clib/clib.cmxs: undefined symbol: caml_thread_sigmask\\\")\")")

Ummm, that looks like -thread is missing, I've tried my best to have this working, but I'm unsure what to do.

Do you know what the problem could be?

Thanks a lot for the help!

[Note, using the pycoq "à la main" approach + Jane Street helpers works]

[ejgallego]

Adding the mt mt_posix predicates to findlib on init did the trick, can we get a way to add this?