...
UnownedDependencyError: Pants cannot infer owners for the following imports in the target scripts/pants/utils/render.py:render-script-src:

  * .lib (line: 1)
...

pants run ./scripts/pants/utils/render.py

python_sources(
    name="render-script-src",
    sources=["render.py", "lib.py", "__init__.py"],  # These files are in the same directory. Tried both with and without the init.py file.
    interpreter_constraints=["==3.9.*"],
    run_goal_use_sandbox=False,
    resolve="render-script",
)

python_requirement(
    name="render-script-requirements",
    requirements=[],
    resolve="render-script",
)

root_patterns

"/scripts/pants/utils"

from scripts.pants.utils import lib
from pants.utils import lib
from utils import lib
from . import lib