On Fri, Jul 17, 2020 at 09:27:54 +0200, Michal Privoznik wrote: > When starting the QEMU driver we load all domain XMLs. This > means, that post parse callbacks are run for each XML, but they > are allowed to fail because we will run them again when starting > a domain. In the case I am fixing, we were unable to look up QEMU > capabilities (in both post parse runs) and reported appropriate > error, sort of. It can be found in the logs, but the caller > doesn't get it because after 5331c4804f4 it is reset. Therefore, > as reported here [1], if we are unable to start QEMU for caps > probing the following will happen: > > virsh start fedora > error: Failed to start domain fedora > error: An error occurred, but the cause is unknown > > 1: https://www.redhat.com/archives/libvir-list/2020-July/msg00673.html > > Fixes: 5331c4804f4 FYI Daniel already posted his version of the fix which does a bit more: https://www.redhat.com/archives/libvir-list/2020-July/msg00804.html