title: How do I work around this problem creating a virtualenv environment with a custom-build Python?
body: <p>I need to run some code on a Linux machine with Python 2.3.4
  pre-installed.  I'm not on the sudoers list for that machine, so I
  built Python 2.6.4 into (a subdirectory in) my home directory.  Then I
  attempted to use virtualenv (for the first time), but got:</p>
  
  <pre><code>$ Python-2.6.4/python virtualenv/virtualenv.py ENV
  New python executable in ENV/bin/python
  Could not find platform dependent libraries &lt;exec_prefix&gt;
  Consider setting $PYTHONHOME to &lt;prefix&gt;[:&lt;exec_prefix&gt;]
  Installing setuptools.........
   Complete output from command /apps/users/dspitzer/ENV/bin/python -c "#!python
  \"\"\"Bootstrap setuptoo...
  
  " /apps/users/dspitzer/virtualen...6.egg:
   Could not find platform dependent libraries &lt;exec_prefix&gt;
  Consider setting $PYTHONHOME to &lt;prefix&gt;[:&lt;exec_prefix&gt;]
  'import site' failed; use -v for traceback
  Traceback (most recent call last):
   File "&lt;string&gt;", line 67, in &lt;module&gt;
  ImportError: No module named md5
  ----------------------------------------
  ...Installing setuptools...done.
  Traceback (most recent call last):
   File "virtualenv/virtualenv.py", line 1488, in &lt;module&gt;
    main()
   File "virtualenv/virtualenv.py", line 529, in main
    use_distribute=options.use_distribute)
   File "virtualenv/virtualenv.py", line 619, in create_environment
    install_setuptools(py_executable, unzip=unzip_setuptools)
   File "virtualenv/virtualenv.py", line 361, in install_setuptools
    _install_req(py_executable, unzip)
   File "virtualenv/virtualenv.py", line 337, in _install_req
    cwd=cwd)
   File "virtualenv/virtualenv.py", line 590, in call_subprocess
    % (cmd_desc, proc.returncode))
  OSError: Command /apps/users/dspitzer/ENV/bin/python -c "#!python
  \"\"\"Bootstrap setuptoo...
  
  " /apps/users/dspitzer/virtualen...6.egg failed with error code 1
  </code></pre>
  
  <p>Should I be setting PYTHONHOME to some value?  (I intentionally named
  my ENV "ENV" for lack of a better name.)</p>
  
  <p>Not knowing if I can ignore those errors, I tried installing nose
  (0.11.1) into my ENV:</p>
  
  <pre><code>$ cd nose-0.11.1/
  $ ls
  AUTHORS    doc/               lgpl.txt     nose.egg-info/  selftest.py*
  bin/       examples/          MANIFEST.in  nosetests.1     setup.cfg
  build/     functional_tests/  NEWS         PKG-INFO        setup.py
  CHANGELOG  install-rpm.sh*    nose/        README.txt      unit_tests/
  $ ~/ENV/bin/python setup.py install
  Could not find platform dependent libraries &lt;exec_prefix&gt;
  Consider setting $PYTHONHOME to &lt;prefix&gt;[:&lt;exec_prefix&gt;]
  Traceback (most recent call last):
   File "setup.py", line 1, in &lt;module&gt;
    from nose import __version__ as VERSION
   File "/apps/users/dspitzer/nose-0.11.1/nose/__init__.py", line 1, in &lt;module&gt;
    from nose.core import collector, main, run, run_exit, runmodule
   File "/apps/users/dspitzer/nose-0.11.1/nose/core.py", line 3, in &lt;module&gt;
    from __future__ import generators
  ImportError: No module named __future__
  </code></pre>
  
  <p>Any advice?</p>