Error with setuptools in virtualenv

Error with setuptools in virtualenv

I had a mess of virtualenv/virtualenvwrapper and virtualenv burrito on my
machine. So I have removed all of it and installed virtualenvwrapper.
Now I have created a virtualenv: mkvirtualenv myenv
I have a simple setup.py
from setuptools import setup
from os.path import dirname, abspath
requirements = []
base_path = abspath(dirname(__file__))
with open(base_path + '/requirements.txt') as r_file:
requirements = r_file.readlines()
setup(
name='x',
version='0.1.0',
long_description="",
packages=['x', 'flume'],
install_requires=requirements,
)
Where 'requirement.txt' has: (its read properly)
distribute==0.6.46
pycassa==1.9.0
FirePython==0.9.0
Flask==0.10.1
Flask-Classy==0.6.3
newrelic==1.12.0.56
pycrypto==2.6
pep8==1.4.6
memorised==1.0.5
jsonpickle==0.4.0
thrift==0.9.0
When I run: python setup.py install inside the virtualenv, I get this error:
(myenv)zengr@x:y$ python setup.py install
running install
error: None
How can I troubleshoot the problem? Any suggestions?