Couchdb: Erlang/OTP 22 Support

[maciozo]

Summary

Erlang/OTP 22 was released in May https://www.erlang.org/news/132. Would it be possible to add support for this?

Desired Behaviour

Support for building/running CouchDB with OTP 22

Possible Solution

Simply adding 22 to the version regex doesn't seem to have been enough, at least. Fails at ==> couchdb (compile).

EDIT: Upon further investigation, it may be a Fauxton compilation issue that's my fault. Checking now.

The compilation is successful without Fauxton - I think I just have some missing dependacies for that.

Additional context

Currently, Void Linux cannot run/build CouchDB, because it provides OTP 22.

[nickva]

Thanks for reporting the issue, @maciozo

I tried installing erlang 22 and elixir build on erlang 22 locally with asdf

$ asdf current
elixir         v1.8.2-otp-22 (set by ASDF_ELIXIR_VERSION environment variable)
erlang         22.0.5   (set by ASDF_ERLANG_VERSION environment variable)

Then did git clean -xffd to clean all current build artifacts, added 22 to rebar.conf.script in main repo and for snappy dependency and got make eunit and make elixir tests to pass.

Created a PR to update snappy:
https://github.com/apache/couchdb-snappy/commit/0f73f2b1b3508c31dd1129e2d7233ff9a469c775

And then one update the main repo with that new snappy version and bumped rebar.config.script values:
https://github.com/apache/couchdb/pull/2070

Though that also required bumping elixir from 1.6.6. to 1.7.4

[maciozo]

Just built from erlang-22-support. Fauxton reports a good installation!

[wohali]

@nickva could you be sure to update apache/couchdb-ci to bump the minimum version of Elixir required to 1.7.4? Thanks.

One line fix: https://github.com/apache/couchdb-ci/blob/master/bin/install-elixir.sh#L31

[nickva]

@wohali thanks for the reminder!

https://github.com/apache/couchdb-ci/pull/22

[nickva]

Documentation PR as well:

https://github.com/apache/couchdb-documentation/pull/425