Normally the test completes in seconds or minutes and reports output as it progresses. In the failing case, it runs for 1h and reports no output at all - it just returns -1.

Example failing job: 

https://beaker.engineering.redhat.com/recipes/20633267#task212121642

The same job rerun on the same system and completing successfully:

https://beaker.engineering.redhat.com/recipes/20637982#task212166810