My box is gentoo 1.4 x86. I emerged cups, efax, and later fax4cups, because I wanted to define a pseudo-printer for faxing over efax (which worked standalone). I never could select a efax:/dev/modem device in the webadmin gui of cups, there was none. After further investigation I found that the backend scripts under /usr/lib/cups/backend, which belong to the fax4cups package, had no exec permission. After issuing a "chmod a+rx" on them all went well. I could create my pseudo-printer with cups' webadmin gui, and even faxing of postscript files works. Reproducible: Always Steps to Reproduce: 1. 2. 3. If you need more info, feel free to contact me :-)
what a stupid mistake, fixed :)