As the summary says, I'm seeing a lot of master-paladin failures for the last few days. Digging in, it seems they are caused by lab network failures. For examples, take a look at https://uberchromegw.corp.google.com/i/chromeos/builders/x86-zgb-paladin/builds/6112. The summary text can be found verbatim in the stdio of the first step. For reference, the master-paladin failure I was investigating is at https://uberchromegw.corp.google.com/i/chromeos/builders/master-paladin/builds/10654.