Comment 18 for bug 1789059

Got it, thanks.

I'm running cinnamon-4.6.5-1 with qt5-base-5.15.0-3 (https://git.archlinux.org/svntogit/packages.git/log/trunk?h=packages/qt5-base). I start Mixxx with '-platform xcb', per default, but needless since Cinnamon runs on X (1.20.8-2). I just removed 'pasuspender' from the official launcher.

The build sources for Arch are at (https://git.archlinux.org/svntogit/community.git/log/trunk?h=packages/mixxx).

I did what you suggested and the call stack is similar, even did a diff between'em. The only change was in one thread that was not blocking on that call (see attached). This is the thread that is running at priority -2 that I mentioned previously, don't know what it is/does.
The first time it was caught on an unknown function at 'libm.so.6' and now it stays in 'clock_nanosleep@GLIBC_2.2.5 ()' at 'libc.so.6'. It's using the majority of CPU of the process, about 5%, even during the hang state.

'strace' of a hang thread shows FUTEX_WAIT_PRIVATE, predictably.

I tested with suspending multiple times with the debugger and there were no further changes, not even after the song had stopped.