error : virPidFileAcquirePath:422 : Failed to acquire pid file '/run/user/1000/libvirt/libvirtd.pid': Resource temporarily unavailable
Solution 1:
Check that libvirtd was running on your system using command
ps -ef | grep libvirtd
move your pid file using command
mv /var/run/libvirtd.pid /var/run/libvirtd.pid.old
stop libvirtd service using command
systemctl stop libvirtd.service
and start again using command
systemctl start libvirtd.service