Hi!

While rebuilding the python related packages against the Python 3.15rc1
version we found that ros2-colcon-core fails to build from source [1].

To fix the errors, I had to apply the following upstream patches:
- upstream commit dbc75ee [2]: Adjust executor test for broader
   compatibility (#739)
- upstream commit c0dbc29 [3]: Fall back when setuptools is too recent
   for symlink install (#735)
- upstream commit 41fb554 [4]: Adjust Python build tests to support
   setuptools >= 80 (#737) (fixes #1146464)

I applied these fixes in the sandbox [5] to be able to build the
packages that depend on ros2-colcon-core, please consider applying the
patches to support the upcoming 3.15 version.

Happy hacking,

[1]: https://debusine.debian.net/debian/r-python-python3.15/artifact/4541776/
[2]: https://github.com/colcon/colcon-core/commit/dbc75eeb851b103db74faec1dd5bfdbb0636b02e
[3]: https://github.com/colcon/colcon-core/commit/c0dbc292b823101d3de71da7bd3d91fdb0b39258
[4]: https://github.com/colcon/colcon-core/commit/41fb5542d4a1d884aa0324f928e5a05396a70179
[5]: https://debusine.debian.net/debian/r-python-python3.15/