doc8 considers include directive paths starting with / to be invalid

[SeanDS]

Include directives like this are valid Sphinx:

.. include:: /somefile.hrst

This is mentioned by the Sphinx developer here. The doc8 linter complains about the above definition though:

docs/source/myfile.rst:1: D000 Problems with "include" directive path:
InputError: [Errno 2] No such file or directory: '/somefile.hrst'.

Sphinx includes the file just fine.