Also, https://github.com/pantsbuild/pants/pull/15689 is a long-requested feature to allow

run

to use the sources directly from the repo instead of sandboxing them. This is necessary for, e.g., Django's

makemigrations

, and other processes that operate on the repo itself and compute output locations relative to the sources it's running on

would this make any non-source files in the build root visible to the python program? if so, it will be also a huge win for me!

Non-source files in the repo are already visible! When you

./pants run

the CWD is the repo root, so if your code `open()`s a relative path in the repo that should work today. The difference is just how the sys.path is set. Today it points to sandboxed copies of the code, after this change it can instead point to the repo directly.