Fix Dockerfile.test parse error in docker-test.yml workflow

[Copilot]

Problem

The docker-test.yml GitHub Actions workflow was failing with a Dockerfile parse error:

ERROR: failed to build: failed to solve: dockerfile parse error on line 13: unknown instruction: poetry

Root Cause

The workflow creates a Dockerfile.test file using a heredoc. Within this Dockerfile, a comment was embedded in the middle of a multi-line RUN command with backslash continuation:

RUN python -m pip install --upgrade pip wheel setuptools && \
    pip install poetry==1.8.3 && \
    poetry config virtualenvs.create false --local || true && \
    # Install only dependencies (skip installing the project itself until after sources copied)
    poetry install --only main --no-root --no-interaction --no-ansi

When a comment appears within a backslash-continued command, it breaks the continuation chain. This causes Docker to interpret poetry install... as a separate Dockerfile instruction rather than part of the RUN command, resulting in the parse error "unknown instruction: poetry".

Solution

Moved the comment to its own line before the RUN command:

# Install only dependencies (skip installing the project itself until after sources copied)
RUN python -m pip install --upgrade pip wheel setuptools && \
    pip install poetry==1.8.3 && \
    poetry config virtualenvs.create false --local || true && \
    poetry install --only main --no-root --no-interaction --no-ansi

This ensures the RUN command with backslash continuation is uninterrupted, allowing Docker to parse it correctly as a single instruction.

Testing

Verified that the generated Dockerfile.test now parses successfully without the "unknown instruction: poetry" error. The RUN command is properly recognized as a single multi-line instruction.

Fixes #1

Original prompt

#1 [internal] load build definition from Dockerfile.test
#1 transferring dockerfile: 1.15kB done
#1 DONE 0.0s
Dockerfile.test:13

11 | COPY pyproject.toml poetry.lock* ./
12 | RUN python -m pip install --upgrade pip wheel setuptools && pip install poetry==1.8.3 && poetry config virtualenvs.create false --local || true && # Install only dependencies (skip installing the project itself until after sources copied)
13 | >>> poetry install --only main --no-root --no-interaction --no-ansi
14 |
15 | # Copy project files

ERROR: failed to build: failed to solve: dockerfile parse error on line 13: unknown instruction: poetry
Error: buildx failed with: ERROR: failed to build: failed to solve: dockerfile parse error on line 13: unknown instruction: poetry

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