OError: [Errno 26] Text file busy: '/...myvirtualenv/bin/python'

Kill Python Processes running on your system with pkill python

I will work

I had the exact same problem :)

virtualenv works (afaik) by modifying a copy of the python executable in the virtualenv directory area.

You must have a process using the virtualenv already so the copy of the python executable is 'in use' (technically it's mmap()'ed into memory whilst it's executing).

Unless you need to change the setup of a virtualenv you don't need to re-run the virtualenv command every time - once it's setup you just activate it when needed.

As to why it happens - It's possible that you have a service running at boot time:

ps -ef | grep python