I’m trying to do a cross-platform build for a Phoenix app, so on my ARM macOS, I’m running
docker buildx build --platform linux/amd64 [more, less relevant options] .
The relevant part of the Dockerfile contains:
FROM hexpm/elixir:1.15.2-erlang-26.0.2-ubuntu-focal-20230126 AS build-stage
# install build dependencies
RUN apt-get update -y && apt-get install -y build-essential git \
&& apt-get clean && rm -f /var/lib/apt/lists/*_*
# prepare build dir
WORKDIR /app
# install hex + rebar
RUN mix local.hex --force && \
mix local.rebar --force
# set build ENV
ENV MIX_ENV="prod"
# install mix dependencies
COPY mix.exs mix.lock ./
RUN mix deps.get --only $MIX_ENV
When it reaches the RUN mix deps.get line, it blows up after a brief moment with BEAM running out of memory:
=> ERROR [build-stage 6/17] RUN mix deps.get --only prod 3.5s
------
> [build-stage 6/17] RUN mix deps.get --only prod:
3.040 no next heap size found: 2305842975251512930, offset 0
3.045
3.045 Crash dump is being written to: erl_crash.dump...done
3.483 qemu: uncaught target signal 6 (Aborted) - core dumped
3.493 Aborted
------
Dockerfile:22
--------------------
20 | # install mix dependencies
21 | COPY mix.exs mix.lock ./
22 | >>> RUN mix deps.get --only $MIX_ENV
23 | RUN mkdir config
24 |
--------------------
Things I’ve already tried:
- Omitting
--platform linux/amd64makes the memory explosion go away. But then the binaries built will be Aarch64 which won’t run on an x64 Linux server. - Skipping
--only prodmakes no difference, getting the deps still has a memory explosion.
I understand this is not a common thing to do, but if someone has an idea on how to solve this, I’d be grateful.
