[libvirt] [RFC] provide error string on blockjob event

Hi, all. There is a patch series [1] that adds reporting qemu blockjob errors to the client on migration. I guess if somebody uses block{copy/pull/commit} he would be glad to see the precise qemu error too. But these operation are asynchronous and blockjob result is provided via event. So what do you think on extending blockjob events to provide error string too? [1] https://www.redhat.com/archives/libvir-list/2016-November/msg00047.html Nikolay