aspect-build
[Bug]: py_binary expression expands to more than one file
What happened?
Using rules_python's py_binary like this:
py_binary(
name = "upstream_py_binary",
srcs = ["say.py"],
main = "say.py",
)
py_binary(
name = "upstream_py_binary2",
srcs = ["say.py"],
main = "say.py",
data = [":upstream_py_binary"],
env = {"FOO": "$(execpath :upstream_py_binary)"},
)
Works fine, but if you do the same with rules_py's py_binary, you get this error:
ERROR: /home/ubuntu/dev/bazelbuild/rules_py/examples/py_binary/BUILD.bazel:9:10: in py_binary rule //examples/py_binary:py_binary2: label '//examples/py_binary:py_binary' in $(location) expression expands to more than one file, please use $(locations //examples/py_binary:py_binary) instead. Files (at most 5 shown) are: [bazel-out/aarch64-fastbuild/bin/examples/py_binary/py_binary, bazel-out/aarch64-fastbuild/bin/examples/py_binary/py_binary.venv.pth, examples/py_binary/say.py]
Version
Development (host) and target OS/architectures: ubuntu 22.04
Output of bazel --version: bazel 7.4.0
Version of the Aspect rules, or other relevant rules from your WORKSPACE or MODULE.bazel file: see repro case below
How to reproduce
On this branch: https://github.com/aspect-build/rules_py/pull/456
bazel build :upstream_py_binary2 works fine
bazel build :py_binary2 fails with the above error
Any other information?
No response
The reason this works in rules_python is that they use an exposed internal method to expand the files, rather than the one on ctx, all Bazel built-in rules exhibit this behavior, iirc there's an open issue upstream for it.
That being said, it likely makes sense to remove the other outputs from files on DefaultInfo.
maybe https://github.com/bazelbuild/bazel/pull/24690 is the better solve here
Yes, this should be fixed in Bazel. I wanted to send a patch myself, but never got time.
This appears to have been resolved by https://github.com/bazelbuild/bazel/pull/24690, available in 8.0.1 and later.
