I created a new Doxygen project and selected all the options I wanted it to generate. One of the options I selected was in the [Wizard] tab, under the Diagrams topic: "Use dot tool from the GraphViz package". I clicked "Run doxygen" and...
Errors.
Specifically, the log file showed:
sh: dot: command not found
error: Problems running dot: exit code=127, command='dot', arguments='"/[path]/Doxygen/html/[filename].dot" -Tpng -o "/[path]/Doxygen/html/[filename].png"'
Most answers that popped up online dealt with the Windows version of Doxygen, but not OS X. Turns out, it's a simple fix. It's looking for /usr/bin/dot which, as I showed earlier, was actually located in /opt/local/bin/dot due to MacPorts.
Switch over to the [Expert] tab, under the Dot topic. Find DOT_PATH and enter /opt/local/bin in that field. If you use the Finder button, which lets you open a dialog window to locate the 'dot' file, it puts in a relative path: ../../../../../opt/local/bin, which actually doesn't always work correctly. Just use the absolute path of /opt/local/bin and you should be good.
Now hitting "Run doxygen" should correctly generate the dependency graphs.
I remember (vaguely) doing something like this a couple years ago, but forgot all the steps, especially the OS X-specific settings (versus the Windows path ones). Hope it helps someone else out there!
