Ошибка сборки firefox 77.0.1

Exception in thread ProcessReader:
Traceback (most recent call last):
  File "/usr/lib64/python3.6/threading.py", line 916, in _bootstrap_inner
self.run()
  File "/usr/lib64/python3.6/threading.py", line 864, in run
self._target(*self._args, **self._kwargs)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/testing/mozbase/mozprocess/mozprocess/processhandler.py", line 1116, in _read
callback(line.rstrip())
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/testing/mozbase/mozprocess/mozprocess/processhandler.py", line 1026, in __call__
e(*args, **kwargs)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mach/mach/mixin/process.py", line 96, in handleLine
line_handler(line)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mozbuild/mozbuild/controller/building.py", line 706, in on_line
self.log(logging.INFO, 'build_output', {'line': message}, '{line}')
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mach/mach/mixin/logging.py", line 54, in log
extra={'action': action, 'params': params})
  File "/usr/lib64/python3.6/logging/__init__.py", line 1374, in log
self._log(level, msg, args, **kwargs)
  File "/usr/lib64/python3.6/logging/__init__.py", line 1444, in _log
self.handle(record)
  File "/usr/lib64/python3.6/logging/__init__.py", line 1454, in handle
self.callHandlers(record)
  File "/usr/lib64/python3.6/logging/__init__.py", line 1516, in callHandlers
hdlr.handle(record)
  File "/usr/lib64/python3.6/logging/__init__.py", line 865, in handle
self.emit(record)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mozbuild/mozbuild/controller/building.py", line 590, in emit
self.fh.write(msg)
UnicodeEncodeError: 'ascii' codec can't encode character '\xf6' in position 229: ordinal not in range(128)


KeyError: 'compile'

  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mozbuild/mozbuild/build_commands.py", line 138, in build
append_env=append_env)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mozbuild/mozbuild/controller/building.py", line 1224, in build
usage = monitor.get_resource_usage()
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mozbuild/mozbuild/controller/building.py", line 476, in get_resource_usage
o['tiers'] = self.tiers.tiered_resource_usage()
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mozbuild/mozbuild/controller/building.py", line 167, in tiered_resource_usage
self.add_resources_to_dict(t_entry, phase=tier)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/python/mozbuild/mozbuild/controller/building.py", line 176, in add_resources_to_dict
end=end, phase=phase, per_cpu=False)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/testing/mozbase/mozsystemmonitor/mozsystemmonitor/resourcemonitor.py", line 477, in aggregate_cpu_percent
data = self.phase_usage(phase)
  File "/var/calculate/tmp/portage/www-client/firefox-77.0.1/work/firefox-77.0.1/testing/mozbase/mozsystemmonitor/mozsystemmonitor/resourcemonitor.py", line 436, in phase_usage
time_start, time_end = self.phases[phase]

Для сборки необходимо в package.use добавить:
dev-python/jsonschema -python_targets_python2_7
dev-python/importlib_metadata -python_targets_python2_7
Установятся необходимые модуля Python.