D7952: rust: add a README

[valentin.gatienbaron (Valentin Gatien-Baron)]

valentin.gatienbaron added inline comments.

INLINE COMMENTS

> gracinet wrote in README.rst:25
> `HGMODULEPOLICY` is for runtime, it can be `rust+c` or `rust+c-allow`. 
> In the first form, not having the Rust extension is a failure, in the second, there's a fallback.

When I tested, setting HGMODULEPOLICY didn't work, perhaps because of what Raphael said.

> Alphare wrote in README.rst:27
> I think you're missing the `-l` option for `run-tests.py`

Well, one can use `-l` to run rust tests, but it's not mandatory?

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7952/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7952

To: valentin.gatienbaron, #hg-reviewers, Alphare
Cc: pulkit, gracinet, Alphare, mjpieters, mercurial-devel