Question

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:

$ Python-2.6.4/python virtualenv/virtualenv.py ENV
New python executable in ENV/bin/python
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
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 <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
'import site' failed; use -v for traceback
Traceback (most recent call last):
 File "<string>", line 67, in <module>
ImportError: No module named md5
----------------------------------------
...Installing setuptools...done.
Traceback (most recent call last):
 File "virtualenv/virtualenv.py", line 1488, in <module>
  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

Should I be setting PYTHONHOME to some value? (I intentionally named
my ENV “ENV” for lack of a better name.)

Not knowing if I can ignore those errors, I tried installing nose
(0.11.1) into my ENV:

$ 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 <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Traceback (most recent call last):
 File "setup.py", line 1, in <module>
  from nose import __version__ as VERSION
 File "/apps/users/dspitzer/nose-0.11.1/nose/__init__.py", line 1, in <module>
  from nose.core import collector, main, run, run_exit, runmodule
 File "/apps/users/dspitzer/nose-0.11.1/nose/core.py", line 3, in <module>
  from __future__ import generators
ImportError: No module named __future__

Any advice?

Answer 1

Have you actually run “make install” on your custom python build? Usually you’ll want to do something like

./configure --prefix=/path/to/installdir  (other options)
make
make install

Note Prefix can be any directory you have full write-permissions to, for example I very often use $HOME/apps on shared-hosting environments.

Then run /path/to/installdir/bin/python, not the one from your build directory. This should create the correct variables, and after that you can install virtualenv. Might be best to install virtualenv using its setup.py:

cd virtualenv_source_dir
/path/to/installdir/bin/python setup.py install

This may require installing setuptools first, using the same method.

Then finally:

# Just to be safe
export PATH="/path/to/installdir/bin:$PATH" 

virtualenv ~/ENV
~/ENV/bin/pip install somepackage # (and such)