Testing fails because iptest.py cannot be found

[vitaut]

When trying to run the tests using the command

$ python -c "import IPython; IPython.test()"

as suggested in the documentation I get the following errors:

**********************************************************************
IPython test group: IPython.config
/usr/bin/python: can't open file 'IPython/testing/iptest.py': [Errno 2] No such file or directory
**********************************************************************
IPython test group: IPython.core
/usr/bin/python: can't open file 'IPython/testing/iptest.py': [Errno 2] No such file or directory
...

and all the tests fail.

Replacing line 384 of iptest.py with the following

subp = subprocess.Popen(["python", "-c", "import os; print os.getcwd()"], env=env)

and rerunning the tests reveals that python starts in the /tmp directory which explains why IPython/testing/iptest.py is not found, although it is not clear why it happens.

I am using the latest version of IPython from the repository and Python 2.7.4 on Ubuntu 13.04.