why can't you forbid subpackages of external modules?

[dpinol]

[tool.importlinter]
include_external_packages = true
root_packages = ["scserver", "scweb", "test"]

[[tool.importlinter.contracts]]
name = "kk"
forbidden_modules = ["pytest_check.check"]
source_modules = ["test"]
type = "forbidden"

With this config I get:
Invalid forbidden module pytest_check.check: subpackages of external packages are not valid.

[seddonym]

You should be able to fix this by adding pytest_check as one of the root packages. Alternatively, change pytest_check.check to just pytest_check.

The reason for this is because Import Linter analyses a graph of the imports between different modules. If you don't include pytest_check as a root package then it will just be added as a single node pytest_check in the graph.

Hope that solves your problem!

[seddonym]

@pwalsh - I've opened a separate ticket for your question, see link above.