Building a Python distribution in Pants 2.13.0 fails for multiple top-level projects layout

[alexey-tereshenkov-oxb]

Given this PR checkout, when running:

$ ./pants package //:my-wheel

15:49:19.67 [ERROR] 1 Exception encountered:
  NoSourceRootError: No source root found for `.`. See https://www.pantsbuild.org/v2.13/docs/source-roots for how to define source roots.

Changing the Pants version to 2.12.0, the wheel can be produced with the same command:

$ ./pants package //:my-wheel
15:51:47.71 [INFO] Initializing scheduler...
15:51:48.11 [INFO] Scheduler initialized.
15:51:51.43 [INFO] Wrote dist/helloworld-0.0.1-py3-none-any.whl

The issue can be fixed by setting root_patterns = ["/"] to keep Pants 2.13.0 happy.

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Adding the root "/" doesn't seem to be necessary as there are no sources in the root.

[benjyw]

This is a known issue, Pants currently requires a source root for some files that shouldn't strictly require them (like requirements.txt).

[alexey-tereshenkov-oxb]

This is a known issue, Pants currently requires a source root for some files that shouldn't strictly require them (like requirements.txt).

Thank you so much, @benjyw, this is great to know. I'll make sure to add this and see if the issue is resolved after a few releases.