MacOS Python 3.7 virtualenv fails?

Question

My system is running MacOS and Homebrew and it recently updated to Python 3.7.

Now, just creating a new virtualenv and trying to use it fails.

FYI, I don't actually need Python 3.7. I didn't upgrade on purpose. I'd prefer the latest stable, supported version, but of course, I want the basics working.

➜  rm -rf ~/.virtualenvs/test
➜  python3 -m venv ~/.virtualenvs/test
➜  vex --path ~/.virtualenvs/test python
zsh: /usr/local/bin/vex: bad interpreter: /usr/local/opt/python/bin/python3.6: no such file or directory

➜  python3
Python 3.7.0 (default, Jun 29 2018, 20:13:13) 
[Clang 9.1.0 (clang-902.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> 

Answer 1

/usr/local/bin/vex file has this as the first line: #!/usr/local/opt/python/bin/python3.6; it's called shebang and it points operating system to the interpreter to run the script. You've uninstalled python3.6 so OS cannot find said interpreter. You need to reinstall vex with python3.7.