2 min read

Somethings should be obvious, but are not, obviously

Update: Apparently, I had accidentally hit a minor bug in pew. This has now been fixed.

Every so often, we spend several hours battling an issue, fighting linux or python or people or thoughts. The solution, often, leaps out when there has been a respite in the constant search for the solution. It’s the “duh” moment, that all of us feel. There is a little self-loathing, and relief at having arrived at solution. It is a moment of great pleasure, that I have learned to relish.

I am currently on a bit of MongoDB binge, and I was setting up a dev environment, using Crunchbang on Virtualbox. Since it is a clean install, I wanted to bootstrap using only pew and pip, which have recently become my favourite part of working in a pure python environment (no more sudo == yay!!)

I followed the instructions to install pew (which is quite straight-forward). All one should need is

    pip install pew

However, when I tried the same, the install worked, but I couldn’t run pew. It couldn’t find all the libraries it needed to load (virtualenv, in this case)

    [email protected]:~$ sudo pip install pew
    Downloading/unpacking pew
    Downloading pew-0.1.9.tar.gz
    Running setup.py (path:/tmp/pip_build_root/pew/setup.py) egg_info for package pew
    ...
    Successfully installed pew virtualenv
    Cleaning up...
    
    [email protected]:~$ pew ls
    Traceback (most recent call last):
    File "/usr/local/bin/pew", line 5, in
    from pkg_resources import load_entry_point
    File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 2707, in
    working_set.require(__requires__)
    File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 686, in require
    needed = self.resolve(parse_requirements(requirements))
    File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 584, in resolve
    raise DistributionNotFound(req)
    pkg_resources.DistributionNotFound: virtualenv

After trying several things, including looking a lot of code in pew, the fix was quite simple. The version of setup-tools that comes default with python2.7 and crunchbang seems flawed.

    [email protected]:~$ sudo pip install -U setuptools
    Downloading/unpacking setuptools from https://pypi.python.org/packages/3.4/s/setuptools/setuptools-2.2-py2.py3-none-any.whl#md5=3b7d84f496aed8c07b91efba4aa197a4
    Downloading setuptools-2.2-py2.py3-none-any.whl (540kB): 540kB downloaded
    Installing collected packages: setuptools
    Found existing installation: distribute 0.6.24dev-r0
    Uninstalling distribute:
    Successfully uninstalled distribute
    Successfully installed setuptools
    Cleaning up...
    
    [email protected]:~$ pew ls
    
    [email protected]:~$ pew new test
    New python executable in test/bin/python
    Installing setuptools, pip...done.
    Launching subshell in virtual environment. Type 'exit' or 'Ctrl+D' to return.
    /home/shiva/.local/share/virtualenvs/test/bin:/home/shiva/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games