Maybe, the project as a whole seems to be under a year old and is under very active development.

Probably 7.0.0 or 3.2.9, where current version is 8.2.6: https://github.com/kennethreitz/pipenv/blob/master/HISTORY.t...

Also, I guess --python 3.4 would be the preferred way to do it, seems to work with either versions or executables.