For instance, see https://pastebin.mozilla.org/8829336 I have DEBFULLNAME=Fabrice Desré in my env.

fabrice@fabrice-ThinkPad-X240:~/dev/builds/obj-fx-desktop$ mach test test_install_receipts.html From _tests: Kept 35218 existing; Added/updated 0; Removed 0 files and 0 directories. Checking for orphan ssltunnel processes... Error running mach: ['test', 'test_install_receipts.html'] The error occurred in code that was called by the mach command. This is either a bug in the called code itself or in the way that mach is calling it. You should consider filing a bug for this issue. If filing a bug, please include the full output of mach, including this error message. The details of the failure are as follows: UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 12: ordinal not in range(128) File "/home/fabrice/dev/b2g-inbound/testing/mach_commands.py", line 243, in test test_objects=tests, **kwargs) File "/home/fabrice/dev/b2g-inbound/python/mach/mach/registrar.py", line 62, in dispatch return fn(**args) or 0 File "/home/fabrice/dev/b2g-inbound/testing/mochitest/mach_commands.py", line 1000, in run_mochitest_general **kwargs) File "/home/fabrice/dev/b2g-inbound/testing/mochitest/mach_commands.py", line 479, in run_desktop_test result = runner.runTests(options) File "/home/fabrice/dev/builds/obj-fx-desktop/_tests/testing/mochitest/runtests.py", line 2075, in runTests self.killNamedOrphans('ssltunnel') File "/home/fabrice/dev/builds/obj-fx-desktop/_tests/testing/mochitest/runtests.py", line 2050, in killNamedOrphans process.run() File "/home/fabrice/dev/b2g-inbound/testing/mozbase/mozprocess/mozprocess/processhandler.py", line 710, in run self.proc = self.Process([self.cmd] + self.args, **args) File "/home/fabrice/dev/b2g-inbound/testing/mozbase/mozprocess/mozprocess/processhandler.py", line 113, in __init__ universal_newlines, startupinfo, creationflags) File "/usr/lib/python2.7/subprocess.py", line 710, in __init__ errread, errwrite) File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child raise child_exception

This is tracked by Bug 1152428.