Asciinema record virtualenv creation

Hello,
I tried to use asciinema to record installation of my python package. It consist of

$ virtualenv env --python=python3.6
$ source env/bin/activate
(env) pip install dbgr

It works until I trie to record it with asciinema. I start asciinema in my system python 2.7., start recording and create and activate virtualenv. But when I try to install dbgr, it get’s installed into python 2.7 including all dependencies (even when the pypi package says it’s for python >= 3.6). Only thing that get’s installed in the environment are the entry_points from the packages. But the packages themself are not there and of course the program doesn’t work.

Recording of what is going on: https://asciinema.org/a/XCZ0RSw1eQSW2vGFAZwD9a9RV You can see it’s not in the env