RemovedInSphinx80Warning in ProjectInfoFactory.__init__

[gareth-rees]

Building a project with Sphinx 7.2.6, I get the following warning (line-wrapped for clarity):

python3.10/site-packages/breathe/project.py:116: RemovedInSphinx80Warning:
Sphinx 8 will drop support for representing paths as strings. Use "pathlib.Path" or "os.fspath" instead.
  self._default_build_dir = os.path.dirname(app.doctreedir.rstrip(os.sep))

I don't know exactly when Sphinx plan to release version 8, but their last release in the version 6 series was 6.2.1, and their latest release in the version 7 series is 7.2.6, so it may not be long now.

Possible solutions include os.path.normpath:

self._default_build_dir = os.path.dirname(os.path.normpath(app.doctreedir))

or conversion to str:

self._default_build_dir = os.path.dirname(str(app.doctreedir).rstrip(os.sep))

or conversion to Path and back again:

self._default_build_dir = str(Path(app.doctreedir).parent)

There may be more cases where code would need to be updated to support Sphinx 8.0. I had a quick look and found one more:

breathe/breathe/renderer/sphinxrenderer.py

Lines 2408 to 2410 in 542ae9b

	dot_file_path = os.path.abspath(
	self.app.confdir + os.sep + project_path + os.sep + dot_file_path
	)

This would need to become:

dot_file_path = os.path.abspath(os.path.join(self.app.confdir, project_path, dot_file_path))