Hi, Sami.
Thank you very much for quickly reply.
> Please let me know if switching to Python 3.7 does not fix this issue for you.
As advised, I compiled using Python-3.7 (Python-3.7.9).
If I simply changed the Python version,
the build did not finish successfully and the same error occurred.
However, when I did a git clone of the edk2 source again and specified the latest master branch,
the build finished successfully.
Thank you for the advice.
Best regards, Shuuichrou.