Recently, Doxygen 1.9.3 made a change to how a specified dot file was handled (with respect to XML output). Previously the file was specified in XML using an absolute path, and the specified dot file was used. Now, doxygen uses a relative path in the XML output and copies the specified dot file to the XML output folder. This causes problems when breathe tries to find the dot file specified because the relative path used in the XML is relative to the doxygen project's root path, the sphinx project usually doesn't exist in the same path.

Possible Solutions

1. Abstract the doxygen project's path and make an absolute path from it using the relative path specified in XML. I need to learn a way to get the XML's path from the context of sphinxrenderer.py.

2. Take this issue upstream since I'm not sure if this is actually desired behavior. See XML output for dot file uses relative path in 1.9.3 doxygen/doxygen#9171

   UPDATE: It is intended behavior. So, I need to figure out how to get an absolute path from the XML file's path

Additional Context

This was discovered in #816 and the temporary solution was to not specify the DOTFILE_DIRS tag in the doxygen config. Although this causes the docs to build without incident, the actual graph is not generated for doxygen 1.9.3. I'm guessing because it doesn't know where to look for the dot files without being told via DOTFILE_DIRS tag.