peterleinchen:

I have just tested on my absolutely-stock N900, and no errors about bad file magic as well. I went to the github repo link, clicked on the file, clicked the 'Raw', and saved the page, which saved as fkdep.html, but was just the plaintext copy of fkdep, so I moved that into /tmp, chmod +x 'ed it, renamed it to just 'fkdep' (for aesthetic purposes) and ran it. Both dpkg -x and dpkg -e worked perfectly without issues.

I'm going to go ahead and bill this as a problem on your end. Can you open the file and view it [Edit 1: by it, I mean the fkdep script itself] to make sure that however you downloaded it, it saved correctly? If you manually selected and copy-pasted from the 'user friendly' default view github provides of code files, then there might be meta characters or maybe line numbers and stuff that got inside the resultant script in the process.