I've observed another occurrence of this test timing out, over on https://builds.apache.org/job/HBase-PreCommit-GitHub-PR/job/PR-1786/3/
The failure message is cryptic, but I think i found the issue. This isn't the HBaseClassTestRule invoking the timeout, it's something in the test, I think in the mini-cluster.
There appears to be a timeout set in some kind of secret manager, which is too aggressive for this mini-cluster test. The last component of the mini-cluster, MapReduce, is finally available at T+273501ms – ~4.5 minutes after process launch. This is how I interpret the log line
a scant 20ms later we get
These thread group names have no meaning to me.
|Reenable the TestExportSnapshot family of tests||Open||Unassigned|