Hi Thomas, <th_huth> is there are reason that qemu-bridge-helper is installed into $libexecdir but qemu-pr-helper is rather installed into $bindir instead?
I'm not familiar with these utilities, but my understanding is $bindir is for user executable binaries. These helpers aren't expected to be started directly by user but by daemon/systemd, so both would belong to $libexecdir. Regards, Phil.