Buildout: use dependencies from system Python

Question

I'm trying to use buildout for a Python package which, when used, depends on 2 extension modules: dbus-python and pygobject. Both modules make buildout fail: dbus-python lacks a setup.py file, while pygobject has one but whose usage is discouraged -- instead configure, make, make install should be used. So, buildout isn't able to setup these dependencies in the development environment.

Here's my buildout.cfg:

[buildout]
develop = .
parts = eggs

[python]
recipe = zc.recipe.eggs
interpreter = python
eggs = foobar

where setup.py for the foobar package contains:

install_requires=['dbus-python', 'pygobject'],

While looking for a solution, I stumbled upon the recipe z3c.recipe.scripts and its ability to utilize system-wide installed eggs. However, when applied to my buildout.cfg ..

[python]
recipe = z3c.recipe.scripts
include-site-packages = true
allowed-eggs-from-site-packages = pygobject, dbus-python
interpreter = python
eggs = foobar    

.. it appears to have no effect (still fails), although both packages (dbus, gobject) are installed in my system Python. The same is true when I remove the allowed-eggs.. line.

My question: Did I got something wrong here on a conceptional level or is there an error in my buildout.cfg?

I know there's zc.recipe.cmmi, a recipe which installs eggs using configure, make, make install. However, simply referencing system Python eggs would be sufficient in my case. I do not need a 100% reproducible environment generated by buildout. Also, dbus-python and pygobject are installed by default on most Linux desktop systems, the environment where foobar is intended to be used.

Answer 1

I haven't gotten the latest 1.5.x buildouts to work with system packages, too. There is one way: pin the versions. That way, zc.buildout 1.5.x will pick it up.

[buildout]
...
versions = versions

[versions]
pygobject = 1.2.3

Alternatively, what I do, you can use the old 1.4.4 buildout (you'll need a special bootstrap.py for that, google it) in combination with osc.recipe.sysegg.

[buildout]
...
parts = 
    ...
    sysegg

[sysegg]
recipe = osc.recipe.sysegg
force-sysegg = true 
eggs =
    dbus-python
    pygobject

I'd personally go for the osc.recipe.sysegg solution, as that's reliable.

Answer 2

You might want to use a CMMI part for each of those poorly behaving python distributions and use the extra-paths option for your python part to make sure the CMMI parts are included in the python path.