Comment # 2 on bug 1070851 from Michael Andres

> A 502 Bad Gateway indicates that the edge server (server acting as a proxy)
> was not able to get a valid or any response from the origin server (also
> called upstream server).

Looks like this occurs in VMs more often. We can only try to mitigate the
impact. Oliver addressed this in https://github.com/openSUSE/zypper/issues/177.