Virtualenv causing setuptools error - virtualenv

Question

I am having trouble running a virtualenv, and I keep getting this same error code: "setuptools pip wheel failed with error code 1"
I saw some pages talking about how this is a discrepancy between different versions of setuptools, but I've uninstalled and reinstalled virtualenv and setuptools in several versions to no results. Does anyone know what's happening here?
Roberts-MacBook-Air:script Rob$ virtualenv venv
New python executable in venv/bin/python
Installing setuptools, pip, wheel...
Complete output from command /Users/Rob/Seedstages/script/venv/bin/python -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip wheel:
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "/Users/Rob/anaconda/lib/python2.7/site-packages/virtualenv_support/pip-7.1.2-py2.py3-none-any.whl/pip/__init__.py", line 13, in <module>
File "/Users/Rob/anaconda/lib/python2.7/site-packages/virtualenv_support/pip-7.1.2-py2.py3-none-any.whl/pip/utils/__init__.py", line 15, in <module>
File "/Users/Rob/anaconda/lib/python2.7/zipfile.py", line 6, in <module>
import io
File "/Users/Rob/anaconda/lib/python2.7/io.py", line 51, in <module>
import _io
ImportError: dlopen(/Users/Rob/Seedstages/script/venv/lib/python2.7/lib-dynload/_io.so, 2): Symbol not found: __PyErr_ReplaceException
Referenced from: /Users/Rob/Seedstages/script/venv/lib/python2.7/lib-dynload/_io.so
Expected in: dynamic lookup
----------------------------------------
...Installing setuptools, pip, wheel...done.
Traceback (most recent call last):
File "/Users/Rob/anaconda/bin/virtualenv", line 11, in <module>
sys.exit(main())
File "/Users/Rob/anaconda/lib/python2.7/site-packages/virtualenv.py", line 832, in main
symlink=options.symlink)
File "/Users/Rob/anaconda/lib/python2.7/site-packages/virtualenv.py", line 1004, in create_environment
install_wheel(to_install, py_executable, search_dirs)
File "/Users/Rob/anaconda/lib/python2.7/site-packages/virtualenv.py", line 969, in install_wheel
'PIP_NO_INDEX': '1'
File "/Users/Rob/anaconda/lib/python2.7/site-packages/virtualenv.py", line 910, in call_subprocess
% (cmd_desc, proc.returncode))
OSError: Command /Users/Rob/Seedstages/script/venv/bin/python -c "import sys, pip; sys...d\"] + sys.argv[1:]))" setuptools pip wheel failed with error code 1
Roberts-MacBook-Air:script Rob$

Answer 1

I would say that Anaconda causes the conflict, though to be more specific, it appears as if Anaconda's virtualenv is the problem. Running which virtualenv on my macbook (where I'm having the same problem) yields /Users/me/anaconda/bin/virtualenv while running it on the linux system I just tested this on yields /usr/local/bin/virtualenv.
So, on OS X, I downloaded virtualenv using /usr/local/bin/pip install virtualenv. This doesn't create a virtualenv binary (or it didn't for me) in the PATH folders, so I had to type this painfully long command:
sudo /usr/local/bin/python ... {the path to virtualenv.py in the system python's site-packages folder} new_env
And that did it. But that's ridiculous. No one wants to do that - even creating links would still be hacking it when you don't need to.
According to the ContinuumIO github page on this very subject, the virtualenv env and source /bin/activate commands are replaced with conda create -n env python=2.7 and source activate env.
Tested on my macbook (running Anaconda2 v4 on OS Yosemite) and it worked out.