Notes about building/using specific external helper applications
The normal procedure for building a Python module applies:
tar xvzf midi-0.2.1.tar.gz cd midi-0.2.1 python setup.py build sudo python setup.py install
However, the midi module includes an alsa driver interface which needs Swig to build and probably does not build at all on recent Linux versions (the last version for the package dates from 2006). Recoll does not need midi sequencer hardware :), so if you don't need for other purposes, you can disable the Alsa interface by editing setup.py and changing the platform name at line 37 (the Alsa thing is only tried on Linux):
37c37 < if platform.startswith('linux'): --- > if platform.startswith('NONE'):
The package should then build and install just fine.