Updating bundled third-party dependencies...

FCollada is already up to date.

Building SpiderMonkey...

SpiderMonkey build options: --disable-tests
           --disable-jemalloc
           --disable-js-shell
           --without-intl-api
           --enable-shared-js
           --disable-jitspew         
patching file js/src/moz.build
patching file js/src/old-configure
patching file python/mozbuild/mozbuild/virtualenv.py
patching file third_party/python/virtualenv/virtualenv/discovery/py_info.py
patching file python/mozbuild/mozbuild/action/process_define_files.py
patching file python/mozbuild/mozbuild/backend/base.py
patching file python/mozbuild/mozbuild/preprocessor.py
patching file python/mozbuild/mozbuild/util.py
patching file python/mozbuild/mozpack/files.py
patching file build/moz.configure/flags.configure
/home/ldh/Downloads/0ad/libraries/source/spidermonkey/mozjs-91.13.1/python/mozbuild/mozbuild/configure/__init__.py:915: SyntaxWarning: invalid escape sequence '\.'
  RE_MODULE = re.compile("^[a-zA-Z0-9_\.]+$")
Traceback (most recent call last):
  File "/home/ldh/Downloads/0ad/libraries/source/spidermonkey/mozjs-91.13.1/build-debug/../js/src/../../configure.py", line 22, in <module>
    from mozbuild.configure import (
  File "/home/ldh/Downloads/0ad/libraries/source/spidermonkey/mozjs-91.13.1/python/mozbuild/mozbuild/configure/__init__.py", line 13, in <module>
    from six.moves import builtins as __builtin__
ModuleNotFoundError: No module named 'six.moves'
ERROR: SpiderMonkey build failed