I *think* this isn't my fault, but I could be wrong, of course :) 03:24:31 FATAL - Automation Error: Can't checkout https://hg.mozilla.org/projects/cedar! 03:24:31 FATAL - Caught exception: environment can only contain strings 03:24:31 FATAL - Caught exception: environment can only contain strings 03:24:31 FATAL - Caught exception: environment can only contain strings 03:24:31 FATAL - Caught exception: environment can only contain strings 03:24:31 FATAL - Caught exception: environment can only contain strings 03:24:31 FATAL - Running post_fatal callback... 03:24:31 ERROR - setting return code to 2 because fatal was called 03:24:31 FATAL - Exiting -1 03:24:31 INFO - Running post-run listener: _summarize 03:24:31 ERROR - # TBPL FAILURE # The non-string environment variable seems to be MOZ_BUILD_DATE which is a unicode value.

this was fixed up in https://bugzilla.mozilla.org/show_bug.cgi?id=858797#c66