Problem with virtualenv in Mac OS X

Question

I\'ve installed virtualenv via pip and get this error after creating a new environment:

selenium:~ auser$ virtualenv new  
New pyt         


        

Answer 1

I got the same problem and I found that it happens when you do not specify the python executable name properly. So for python 2x, for example:

virtualenv --system-site-packages -p python mysite

But for python 3.6 you need to specify the executable name like python3.6

virtualenv --system-site-packages -p python3.6 mysite

Answer 2

In case anyone in the future runs into this problem - this is caused by your default Python distribution being conda. Conda has it's own virtual env set up process but if you have the conda distribution of python and still wish to use virtualenv here's how:

1. Find the other python distribution on your machine: ls -ls /usr/bin/python*

2. Take note of the availble python version that is not conda and run the code below (note for python 3 and above you have to upgrade virtualenv first): virtualenv -p python2.7(or your python version) flaskapp

Answer 3

On on OSX 10.6.8 leopard, after having "upgraded" to Lion, then downgrading again (ouch - AVOID!), I went through the Wolf Paulus method a few months ago, completely ignorant of python. Deleted python 2.7 altogether and "replaced" it with 3.something. My FTP program stopped working (Fetch) and who knows what else relies on Python 2.7. So at that point I downloaded the latest version of 2.7 from python.org and it's installer got me up and running - until i tried to use virtualenv.

What seems to have worked for me this time was totally deleting Python 2.7 with this code:

sudo rm -R /System/Library/Frameworks/Python.framework/Versions/2.7

removing all the links with this code:

sudo rm /usr/bin/pydoc
sudo rm /usr/bin/python
sudo rm /usr/bin/pythonw
sudo rm /usr/bin/python-config

I had tried to install python with homebrew, but apparently it will not work unless all of XTools is installed, which I have been avoiding, since the version of XTools compatible with 10.6 is ancient and 4GB and mostly all I need is GCC, the compiler, which you can get here.

So I just installed with the latest download from python.org.

Then had to reinstall easy_install, pip, virtualenv.

Definitely wondering when it will be time for a new laptop, but there's a lot to be said for buying fewer pieces of hardware (slave labor, unethical mining, etc).

Answer 4

If you continue to have trouble with virtualenv, you might try pythonbrew, instead. It's an alternate solution to the same problem. It works more like Ruby's rvm: It builds and creates an entire instance of Python, under $HOME/.pythonbrew, and then sets up some bash functions that allow you to switch easily between versions. Where virtualenv shadows the system version of Python, using symbolic links as part of its solution, pythonbrew builds entirely self-contained installations of Python.

I used virtualenv for years. It's a decent solution, but I've switched to pythonbrew lately. Having completely self-contained Python instances means that installing a new one takes awhile (since pythonbrew actually compiles Python from scratch), but the self-contained nature of each installation appeals to me. And disk is cheap.

Answer 5

I did the following steps to get virtualenv working :

Update virtualenv as follows :

==> sudo pip install --upgrade virtualenv

Initialize python3 virtualenv :

==> virtualenv -p python3 venv

Answer 6

I ran into a variation of this "not functioning" error. I was trying to create an environment in a folder that included the path ".../Programming/Developing..." which is actually "/Users/eric/Documents/Programming:Developing/"

and got this error:

ImportError: No module named site
ERROR: The executable env/bin/python2.7 is not functioning
ERROR: It thinks sys.prefix is u'/Users/eric/Documents/Programming:Developing/heroku' (should be u'/Users/eric/Documents/Programming:Developing/heroku/env')
ERROR: virtualenv is not compatible with this system or executable

I tried the same in a different folder and it worked fine, no errors and env/bin has what I expect (activate, etc.).