new developer: cssutils error in hello_world plugin

OK: I got the development environment working and was able to insert
some print statements and see the results in the terminal after running
'calibre-debug -g'

For the next step, I tried loading the hello_world plugin.
One attempting a conversion, I get the following error:

RuntimeError: You need cssutils >= 0.9.9 for calibre

I see that cssutils is NOT in the sources downloaded with bzr,
although there are .pyo files for cssutils in the /Application/calibre.app
bundle. (I'm working on MacOSX)

So is the issue that there is no cssutils in the source tree ?

Or is the problem that the cssutils in the Application bundle is the wrong version? (I'm running calibre 0.8.48)

And how do I fix this ?

-- sdm