[arm64+otp 25+qemu] `mix local.hex --force` hangs

We haven’t been able to start using Erlang 25, yet, because I’ve been unable to get our base images built with it. Half of our developers use Macs with the new arm processors, so we’ve switched to a process that builds our images with multi arch support.

I’ve created a dumbed down process as an example of how we build it using Github Actions, here:

You can see here where this problem happens with all supported versions (from Docker Hub) when using Erlang 25:

I stopped it after 12.5 minutes.

On an ubuntu machine I have I can also duplicate this hanging:

docker buildx build --platform linux/arm64,linux/amd64 -t test-arm64-qemu-issue --build-arg ELIXIR_VERSION=1.13.4 --build-arg ERLANG_VERSION=25.0 --build-arg ALPINE_VERSION=3.16.0 .

Has anyone had any luck with this?

I don’t know if this is your problem, but because of bugs in qemu when emulating arm64 the JIT does not work there, so you need to run the arm64 docker images on a native arm64 machine, or disable the JIT (which is done when compiling Erlang).

It should manifest as a segfault and not as a hang, but maybe something is masking the segfault.

Edit: You can find some more information here: OTP 25.0-rc3 (release Candidate 3) is released - #25 by jhogberg - Erlang News - Erlang Programming Language Forum - Erlang Forums

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