libksane seems to break QProcess::start calls

[Tobias Leupold]

Am Donnerstag, 3. März 2022, 19:06:21 CET schrieb Stefan Brüns:
> Are you using either Qt5 < 5.15 or a kernel version which does not support
> CLONE_FD? - then you are relying on SIGCHLD for process exit notification.
> 
> CLONE_FD: https://lwn.net/Articles/636646/
> Qt5: https://codereview.qt-project.org/c/qt/qtbase/+/108456/
> 
> sane-backends/backend/plustek-usbhw.c messes with the signal handlers and
> fails to restore it: `sigaction(..., ..., NULL)`

I use Qt 5.15.2 and Gentoo's kernel 5.15.16. Is there something I can check to 
figure out if this could cause the problem? Apparently, there's no kernel 
option I can set?

Apart from that, the scanner in question actually does use the plustek 
backend! I fear there's no way to fix this in my code?!