Transform oasis2opam into an OASIS command plugin of OASIS

[gildor478]

oasis2opam is tightly linked to OASIS and we should make sure it is always in sync with oasis. One way to achieve that, is to make it a plugin of OASIS. In this case we will be sure that the parsing of _oasis files is up to date.

I have been hit by this bug a few time, because oasis2opam was using an old parser from OASIS that didn't handled some special features (like AlphaFeatures and BetaFeatures introduced recently).

[Chris00]

I am not against it. What route should we follow for integration? Also, this will entail some changes to OASIS because, for example, functions added to OASISVersion (in the Version module) such as min, max,... will need to go into that module (and version_compare will be deprecated and renamed compare in order to apply seamlessly the Set functor). Is it OK with you?

[gildor478]

Here is the "documentation":
https://github.com/ocaml/oasis/blob/master/HACKING.md#creating-plugins

There is an example in the documentation. You probably don't need to change anything in OASISVersion, because you can keep the exact same structure, except that you'll have an extra library.

I can actually send you a PR with a little bit of shuffling around to create the plugin -- if you can wait for it.

[Chris00]

Ah, OK. I misunderstood, I thought you wanted oasis2opam to be merged into oasis.

[Chris00]

My code depends on Str. When I try to execute the plugin, I get

E: Dynlink error while loading '2opam': error loading shared library: /home/trch/.opam/4.03.0/lib/ocaml/str.cmxa: invalid ELF header

[gildor478]

Can you publish your version to a branch, so that I can test it myself ?

unrelated: can we discuss the '2opam' name, I would vote for to-opam or opam-convert...

[Chris00]

On 2016-12-12, Sylvain Le Gall wrote: Can you publish your version to a branch, so that I can test it myself ?

Here is is: https://github.com/Chris00/oasis2opam/tree/plugin

unrelated: can we discuss the '2opam' name, I would vote for to-opam or opam-convert...

I'd like to keep it reasonably short, so "to-opam" is OK with me.

[gildor478]

Solved:
ocaml/oasis@63aa763

You can pin the dev-repo in a few hours when opam/testing will be promoted.

[Chris00]

It sort of works but I get a segfault if the state has to be synchronized. Way to reproduce:

rm ~/.opam/oasis2opam.cache
oasis 2opam

The same happens when trying to generate the files

oasis 2opam https://github.com/mmottl/sqlite3-ocaml/releases/download/v4.1.0/sqlite3-ocaml-4.1.0.tar.gz

I haven't investigated but may it be due to the unix dependency — trying to load it while already present in oasis?

[gildor478]

Tracking bug:
https://forge.ocamlcore.org/tracker/index.php?func=detail&aid=1726&group_id=54&atid=291

I will fix it for OASIS 0.4.9, expect to have to test a few version to make sure it is working before the release.

[Chris00]

OK. Keep me posted about your progress — I can pin oasis when you are ready to test if you like.