macでThe path /usr/local/bin/python3 (from --python=/usr/local/bin/python3) does not exist

下記でどこのpythonが使われているか確認して

$ which python3

/Users/a/.pyenv/shims/python3

 

使われてるpythonで仮想環境を作る

mkvirtualenv --no-site-package --python /Users/ha/.pyenv/shims/python3 env1