$> PYTHONPATH=/home/yoh/deb/perspect/FingerPrint /home/yoh/deb/perspect/FingerPrint/bin/fingerprint -v -d namd_compute.swirl 
Usage: fingerprint [-q|-c|-y|-d|-i] [options] inputfile1 ... inputfileN

fingerprint: error: The file output.swirl could not be opened on this system: [Errno 2] No such file or directory: 'output.swirl'.

why output.swirl if, following --help, I did provide the file to open?

NB initially thought just to suggest in my repy on https://github.com/lclementi/FingerPrint/issues/1 but decided that it might be worth a separate "thread"

Have you approached incorporation of information on the origins of the packages?

i.e. there could be multiple binary package repositories providing them for the system to be fingerprinted on. And per se package version alone might not be sufficient to identify the origin of a package. So -- wouldn't it make sense to include such information into the .swirl (i.e. packageX of version Y cames from repository Z on date D, and here is the information on that repository: URL, name, ...).

If you see a good fit for that within FingerPrint -- I could possibly contribute the Debian-related pieces

The beauty of Python is to be usable across platforms. Figuring out/implementing needed functionality to operate on OSX would be desirable.