python virtualenv on windows: Fatal error in launcher: Unable to create process using '"'

Question

I have created a virtualenv in python 2.7 (Anaconda) on a dev machine and (after package installation) copied it to another windows machine in a PROD setting (no communication to outside). Executing any of the installed ".exe" entry points for a program in the virtualenv produces this error on the target machine however runs fine on the source machine:

(env) D:\app\pyvenv>env\Scripts\pip.exe
Fatal error in launcher: Unable to create process using '"'

The location of python installation on both machines is set to the same folder: C:\ProgramData\Anaconda2

Also see my additional notes at the bottom of this post. thanks

Answer 1

in my case, I previously changed the name of the python.exe executable to python3.exe so when I run:

virtualenv project1_env

it can't locate the python.exe if that was your case too .. just rename it again to python.exe and it should work.

Answer 2

In my case I solve by upgrading pip using following code in activate environment.

python -m pip install --upgrade pip