Traceback (most recent call last):
File "/usr/bin/fix_noto_cjk_thin.py", line 88, in <module>
main(sys.argv)
File "/usr/bin/fix_noto_cjk_thin.py", line 84, in main
fix_font(font_filename)
File "/usr/bin/fix_noto_cjk_thin.py", line 32, in fix_font
assert source_filename.endswith(".otf")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError