Tool

isort

doesn't handle

src_paths

from

.isort.cfg

correctly. If you have namespaced packages implemented in different parts of the repo, then in order for isort to consider any modules exposed in these namespaces first-party imports, you need to add the paths explicitly in the configuration (https://github.com/PyCQA/isort/issues/1704). When running isort with Pants, this does not work (version 5.10.1):

./pants fmt --only=isort path_to_file_that_imports_firstparty_namespaced_modules

reports isort made no changes, but

isort path_to_file_that_imports_firstparty_namespaced_modules

makes the expected change in grouping. One clue is

isort --show-config

reveals the

src_paths

field to be fully qualified, even though they are only specified relative to the configuration root, whereas the same command ran by Pants shows they're still relative. Pants v2.10rc2.

Can you open an issue for this at https://github.com/pantsbuild/pants/issues/new/choose ?

Certainly.

Can you post a link to the issue when you have it? Thanks