[210] ./mach build Error running mach: ['build'] The error occurred in mach itself. This is likely a bug in mach itself or a fundamental problem with a loaded module. Please consider filing a bug against mach by going to the URL: https://bugzilla.mozilla.org/enter_bug.cgi?product=Core&component=mach If filing a bug, please include the full output of mach, including this error message. The details of the failure are as follows: MozconfigFindException: MOZCONFIG environment variable refers to a path that does not exist: mozconfig-opt File "/Users/ekr/dev/mozilla-inbound/python/mach/mach/main.py", line 305, in run return self._run(argv) File "/Users/ekr/dev/mozilla-inbound/python/mach/mach/main.py", line 391, in _run instance = cls(context) File "/Users/ekr/dev/mozilla-inbound/python/mozbuild/mozbuild/base.py", line 532, in __init__ dummy = MozbuildObject.from_environment(cwd=context.cwd) File "/Users/ekr/dev/mozilla-inbound/python/mozbuild/mozbuild/base.py", line 163, in from_environment config = loader.read_mozconfig(mozconfig) File "/Users/ekr/dev/mozilla-inbound/python/mozbuild/mozbuild/mozconfig.py", line 156, in read_mozconfig path = self.find_mozconfig() File "/Users/ekr/dev/mozilla-inbound/python/mozbuild/mozbuild/mozconfig.py", line 102, in find_mozconfig 'does not exist: ' + env_path)