Having an issue building a docker image to be used for an aws lambda function. I can build it locally, but get an error in a github actions pipeline:

Successfully built the wheel simplejson-3.17.2-cp39-cp39-linux_x86_64.whl from the sdist simplejson-3.17.2.tar.gz but it is not compatible with the requested foreign target complete platform cp311-cp311-manylinux_2_26_x86_64

The error message tells you most of what the problem is - the wheel is being built for Python 3.9 but the target platform is Python 3.11; since it’s an

sdist

the package is built from a source distribution. Is there a difference in Python version between your Github Actions pipeline and your local machine?

I'm not sure why it's building with Python 3.9. The interpreter constraints are set to 3.11 in pants.toml and BUILD files, and I'm installing 3.11 in the build pipeline:

steps:
      - name: Checkout
        uses: actions/checkout@v4
      - name: Install python
        uses: actions/setup-python@v4
        with:
          python-version: 3.11.5
      - name: Initialize Pants
        uses: pantsbuild/actions/init-pants@v5-scie-pants
      - name: Build
        id: build-image
        run: |
            pants package path/to/docker:image

Hmm, interesting. I notice that your Docker image depends on a specific Python source - is that intentional, or are you intending to package a PEX file into the image instead?

It was intentional, but not sure if it's necessary in this case? It's there because it's to be deployed as a python aws lambda function, and this suggests such a base image: https://docs.aws.amazon.com/lambda/latest/dg/python-image.html

The dependency in that Pants example is from the Docker image target to the lambda function target, not to a specific source file. That might be the issue, unless

dep/path/main:my_func

is a lambda function

It is a lambda function:

python_aws_lambda_function(
    name="my_func",
    handler="run.py:lambda_handler",
)

Hmm yeah and I see that you already pass in the value of

runtime

via the defaults - but what happens if you explicitly set the lambda function runtime to

python3.11

?

I think that should be set as default with this BUILD file at the root? I'll try setting it explicitly in any case

__defaults__(
    {
        (
            python_sources,
            python_tests,
            python_test_utils,
            python_aws_lambda_function,
            python_aws_lambda_layer,
            pex_binary,
        ): {
            "resolve": "my_resolve",
        },
        (python_sources, python_tests, python_test_utils, pex_binary): {
            "interpreter_constraints": ["==3.11.*"],
        },
        (python_aws_lambda_function, python_aws_lambda_layer): {"runtime": "python3.11"},
    }
)