[DiapDealer]

Is that the Debian unstable Sigil package, or did you compile Sigil yourself? If the former, you should check with the package maintainer. He's always been pretty accessible in the past.

The last time I saw that error on Linux (that prevented Sigil from launching), I actually had to "Pull a Windows" and shut down and reboot. I think my video driver kernel modules had updated at the same time Sigil had, or some such.