Nevow doesn't work with buildout, due to the fact that it imports itself in setup.py

This should be fixed in the next release. See #2527.

Using setuptools does not fix the fact that there is still an import from a file that assumes that Twisted is already in the system path, which is not necessarily true at install time.

This may be fixed by adding an 'install_requires' in the setup dictionary when using setuptools.

Can you describe the user-facing misbehavior which is still present? It sounds like it has something to do with installing Nevow when Twisted is not installed, but it'd be great if you could go into some detail.

When using easy_install or buildout, they automatically grab dependencies listed in the setup dictionary from the PyPi?. They don't necessarily have the same system path as your python executable, especially with buildout (virtual environment like installation system).

Nevow isn't installable with either of these because setup.py imports from nevow which in turn imports from Twisted in order to generate the version string.

I checked out the subversion trunk and modified the setup.py to add the 'install_requires=Twisted?', but that does not add Twisted to the path at setup time. There is a separate 'setup_requires' parameter that I think, but that places eggs in odd places.

There are a few ways to take care of the problem, one would be adding a try/except block around the version import with a fallback to a hardcoded version of some kind. This is the route that others seem to be taking because it simplifies things quite a bit.

Fixing the half-traceback reported in the description.

I've tried to update the summary to reflect a bit more clearly what is going on here. I've removed easy_install from the summary, since easy_install nevow works for me in the various configurations in which I've tried it. (Granted, I haven't been exhaustive, but it's very hard to be exhaustive with any configuration related to distutils.)

I assume that buildout invokes easy_install in some configuration where the system path is different from the install-target path. By the way, since setuptools aggressively tries to make sure that you absolutely will be able to import everything no matter what, I'm curious as to how one convinces easy_install to work at all in such a configuration.

It would be helpful if you could provide reproduction instructions; assume we don't know anything at all about buildout, because we don't.

I've also reassigned this to zooko since he seems more interested in setuptools than anyone else. I hope his interest endures :).

(Also: I added a link to the "buildout" site in the description.)

I'm also going to say this is a feature request, rather than a bug, because "works with buildout!" isn't advertised anywhere in Nevow. Arguably the fact that it doesn't work out of the box is a bug in buildout, not Nevow.

By the way, easy_install doesn't work if you don't already have Twisted installed.

This is a duplicate of #2699.