Really like diagnostics, but I noticed that a whole pile of debug output disappeared when I started testing against the bigpipe master branch rather than the installed module.

Turned out I had a DEBUG environment variable of:

DEBUG=bigpipe*,rtc*

While this is considered two patterns by debug at the moment I think diagnostics is trying to match against this as a single pattern. Once I dropped the pattern back to the following everything was fine:

DEBUG=bigpipe*