`factored_vocab.cpp`: error: variable 'v' set but not used [-Werror,-Wunused-but-set-variable]

[Amit Moryossef]

Bug description

make fails out of the box, says

/bergamot-translator/3rd_party/marian-dev/src/data/factored_vocab.cpp:133:20: error: variable 'v' set but not used [-Werror,-Wunused-but-set-variable]
    for (WordIndex v = 0; io::getline(in, line); v++) {
                   ^

How to reproduce

Minimal reproduction in Docker, should take 3-5 minutes to get to the error /emsdk/upstream/emscripten/emmake make -j2

# python required by emcmake
FROM python:3.9.13

RUN apt-get update
RUN apt-get install -y git git-lfs cmake

# WASM prerequisites
RUN git clone https://github.com/emscripten-core/emsdk.git
WORKDIR emsdk
RUN ./emsdk install 3.1.8
RUN ./emsdk activate 3.1.8

# Compile
WORKDIR /
RUN git clone https://github.com/browsermt/bergamot-translator.git
WORKDIR bergamot-translator
RUN mkdir build-wasm

WORKDIR build-wasm
RUN /emsdk/upstream/emscripten/emcmake cmake -DCOMPILE_WASM=on -DWORMHOLE=off ../
RUN /emsdk/upstream/emscripten/emmake make -j2
RUN bash ../wasm/patch-artifacts-import-gemm-module.sh

ENTRYPOINT ["/bin/bash"]

[Amit Moryossef]

More information: This only happens on an arm based macbook. using --platform linux/amd64 the build is substantially slower, but does not fail.