Error when building docs from release sources due to Git repo not being present

[eksperimental]

Elixir and Erlang/OTP versions

Erlang/OTP 27 [erts-15.2.7.1] [source] [64-bit] [smp:10:10] [ds:10:10:10] [async-threads:1] [jit]

Elixir 1.19.1 (compiled with Erlang/OTP 27)

Operating system

MacOS

Current behavior

❯ make docs
==> ex_doc (elixir)
CANONICAL= bin/elixir ../ex_doc/bin/ex_doc "Elixir" "1.19.3" "lib/elixir/ebin" --main "Kernel" --source-url "https://github.com/elixir-lang/elixir" --source-ref "" --logo lib/elixir/pages/images/logo.png --output doc/elixir --canonical "https://hexdocs.pm/elixir/" --homepage-url "https://elixir-lang.org/docs.html"  --config "lib/elixir/scripts/elixir_docs.exs"

16:58:23.729 [error] beam/beam_load.c(180): Error loading module 'Elixir':
  module name in object code is elixir



16:58:23.903 [error] beam/beam_load.c(180): Error loading module 'Elixir.PATH':
  module name in object code is 'Elixir.Path'



16:58:23.914 [error] beam/beam_load.c(180): Error loading module 'Elixir.PORT':
  module name in object code is 'Elixir.Port'


View "html" docs at "doc/elixir/index.html"
View "epub" docs at "doc/elixir/Elixir.epub"
bin/elixir lib/elixir/scripts/docs_config.exs "elixir"
fatal: not a git repository (or any of the parent directories): .git
** (MatchError) no match of right hand side value:

    {"", 128}

    lib/elixir/scripts/docs_config.exs:7: (file)
    (elixir 1.19.3) lib/code.ex:1613: Code.require_file/2
make: *** [docs_elixir] Error 1

besides the beam_load.c errors, you can see the crash of lib/elixir/scripts/docs_config.exs.
The culprit is that it expects a Git repo to be present and it is not there.

What it is trying to do it to obtain a list of Elixir releases from the Git tags.

A possible solution would be to build a list of Elixir versions and store it in a VERSIONS file, and read from it.

Expected behavior

Not to crash

[josevalim]

Let's document that Git is a dependency. We have no plans to maintain an additional file, given all this information is on git. Thanks! I will drop a comment on the make docs PR.

[eksperimental]

Well, in that case what we can do then is adapt lib/elixir/scripts/docs_config.exs to not to crash and fall back to an empty list of Elixir versions. That'd be the best of both worlds I guess. I can contribute the PR.

[josevalim]

I don't see a reason to optimise for this case. I'd prefer to fail and make sure the docs are built correctly, otherwise one day part of our tooling will fail and we will publish docs without versions, without noticing it.

[eksperimental]

Fair enough. I have left a comment in the other PR regarding git as a dependency not being the real issue.

[josevalim]

Sorry, I understand the issue now. Yes, we should check if there is a .git folder at the root and log that versions are being skipped because we are not in a git repo. Thank you!

[eksperimental]

So we fall back and not crash?

[josevalim]

If there is .git folder, we make the list empty, yeah.

[eksperimental]

Ok. I will submit a PR tomorrow then.