I agree that this might use a little more clarification, but this isn't the right approach either, as these commands don't represent different "modes".  `setup.py develop` runs `setup.py build_ext --inline` as a sub-command.  The point of the latter is that it copies build extension modules into the source tree so that they can be directly imported.  Rerunning `setup.py develop` has the same effect as running `setup.py build_ext --inline`--it's also just overkill since I think it will also recompile any modified python files, recreate the .egg-link file, etc.