Running `mix gettext.extract` doesn't extract new messages with Elixir 1.15

[linusdm]

I'm seeing an issue on new Phoenix projects that run on elixir 1.15. When the mix gettext.extract task is run, it doesn't pick up new messages anymore (nor does the same mix task with the --check-up-to-date option signal missing messages).

Removing the _build folder triggers the task to pick new messages up again, so it appears to be a cache/recompilation problem.

Reproducing is straightforward:

• install and use elixir 1.15 (with asdf: asdf install elixir 1.15.0-otp-25 && asdf global elixir 1.15.0-otp-25)
• I've tested with latest Phoenix installer version (v1.7.6), so ensure this version is installed with mix archive.install hex phx_new 1.7.6
• Create a new default Phoenix project
• Run gettext extract mix task: mix gettext.extract --merge (this initialises all po/t files)
• Change or add any call to gettext/1 (there are some calls in the core_components.ex file).
• Run gettext extract mix task: mix gettext.extract --merge

The last step should result in a new message being extracted to the po/t files, but that's not the case anymore. Running the same procedure with elixir 1.14 does extract a new message.

[linusdm]

Diving deeper into this I can see the project is not actually being force-compiled, as is expected, with the extract mix task. The recompilation is needed to make sure all the calls to gettext end up in the pot files.

There are some steps involved to trigger a forced compilation: https://github.com/elixir-gettext/gettext/blob/main/lib/mix/tasks/gettext.extract.ex#L114-L125

I'm not sure how these mix tasks all come together.

When I replace this line, in the aforementioned function:

Mix.Task.run("compile")

with this line

Mix.Task.run("compile", ["--force"])

the compilation seems to be triggered again, resulting in the extract task to work as expected. I'm sure this is quite naive, and has undesired consequences.

It seems to me that the "trick" with making the compiler manifest stale, doesn't work anymore. When Mix.Task.run("compile") is called the first time, it now does a "normal" compilation, which in most cases is doing nothing, as it's not being forced. The second call to Mix.Task.run("compile.elixir", ["--force"]) is a no-op, as it has been run now by the first overarching task.

Replacing this whole implementation with a single call like this (explicitly omitting everything related to the manifest files, and calling the "regular" compile mix task) also works:

defp force_compile do
  Mix.Task.rerun("compile.elixir", ["--force"])
end

But I'd be surprised if that would be correct in all cases, as I suspect there were reasons to set things up as they are now. For example: is it enough to force compilation only with the elixir compiler, or can other compilers also add to the messages being extracted? Rerunning the regular "compile" instead of the "compile.elixir" task with the --force option can also work. But then again, why were things as complicated as they were with the manifest files. And all this doesn't explain why resetting the date of the manifest files doesn't trigger a force compile anymore since elixir 1.15 (which is my hypothesis).

[linusdm]

I’m suspecting this has something to do with this change: Store timestamps in manifests · elixir-lang/elixir@ce67dd6 · GitHub Manipulating the last-modified date of the manifest file alone isn’t enough anymore, as there are now timestamps being stored in the manifest file itself.