I should clarify first that I haven't reproduced the following bug specifically with venv. I was asked to raise this here after raising an identical issue about virtualenv (https://github.com/pypa/virtualenv/issues/1154); a GitHub user told me this would also apply to venv. 

The bug with virtualenv is that it errors if passed a directory that contains a $ (dollar symbol). $ is a valid character for Windows directory names, filenames, and usernames. So running something simple like `python3 -m venv` (presumably) can fail in some valid Windows directories. 

The full error traceback for virtualenv is available at the above GitHub URL. A commenter in the virtualenv project (see https://github.com/pypa/virtualenv/issues/457#issuecomment-377159868) suggested that this happens because the directory path is passed as-is (with $) to distutils, and distutils is seeing the text following the $ as a placeholder and trying to replace it with a variable, which isn't found.