Fix LegacyKeyValueFormat report from docker build: aarch64-gnu-debug

[homersimpsons]

Part of #152305

r? @marcoieni

[marcoieni]

The multiline way in which you set environment variables isn't equivalent to before.

Try with this Dockerfile:

FROM alpine:3.20

ENV SCRIPT \
  python3 ../x.py --stage 2 build && \
  python3 ../x.py --stage 2 test tests/run-make tests/run-make-cargo

CMD ["sh", "-lc", "printf 'SCRIPT=<%s>\\n' \"$SCRIPT\""]

$ docker build -t env-test .
docker run --rm env-test

prints an output that is trimmed (no space at begin or end)

SCRIPT=<python3 ../x.py --stage 2 build &&   python3 ../x.py --stage 2 test tests/run-make tests/run-make-cargo>

While the following dockerfile (taken from your pr):

FROM alpine:3.20

ENV SCRIPT=" \
  python3 ../x.py --stage 2 build && \
  python3 ../x.py --stage 2 test tests/run-make tests/run-make-cargo"

CMD ["sh", "-lc", "printf 'SCRIPT=<%s>\\n' \"$SCRIPT\""]

prints an output that has spaces at the beginning:

SCRIPT=<   python3 ../x.py --stage 2 build &&   python3 ../x.py --stage 2 test tests/run-make tests/run-make-cargo>

[homersimpsons]

Thanks for your feedback @marcoieni. In fact there is a leading space change. I do not recall if I spotted this, but I think this is not an issue.

The only alternative I can think of is to inline the first line making this potentially harder to read:

-ENV SCRIPT=" \
-  python3 ../x.py --stage 2 build && \
+ENV SCRIPT="python3 ../x.py --stage 2 build && \
  python3 ../x.py --stage 2 test tests/run-make tests/run-make-cargo"

In fact the \ does not trim the leading space in the subsequent lines (this can be observed with the second set of whitespaces after the &&) so ENV SCRIPT="\ still has 2 leading whitespaces.

The documentation https://docs.docker.com/reference/build-checks/legacy-key-value-format/ does not mention this difference, so I do not know if that is expected on docker side. I opened docker/docs#24227.

Do you prefer:

1. I keep it like this (with leading space)? (I can remove 1 out of 3 leading space with "\ instead of " \)
2. I inline the first line (remove the leading spaces)?
3. Other?

[marcoieni]

I prefer option 2, so that the env var doesn't have leading whitespaces. Your diff looks good! 👍

Probably the scripts will work anyway, but bash is weird so I prefer to change the Dockerfiles without affecting their behavior.

[homersimpsons]

I prefer option 2, so that the env var doesn't have leading whitespaces.

Okay, I updated both SCRIPT and RUST_CONFIGURE_ARGS so this is consistent.

Probably the scripts will work anyway, but bash is weird so I prefer to change the Dockerfiles without affecting their behavior.

I can alternatively update only the SCRIPT environment variable if we want to distinguish between "bash scripts" and the other.

[marcoieni]

@bors try jobs=aarch64-gnu-debug

[rust-bors]

☀️ Try build successful (CI)
Build commit: 1d1589a (1d1589a68549b48bb33fe49281c4f8aeb006159e, parent: 6f54d591c3116ee7f8ce9321ddeca286810cc142)

[marcoieni]

@bors r+ rollup=always

[rust-bors]

📌 Commit 6df2169 has been approved by marcoieni

It is now in the queue for this repository.