Distutils2 - Logilab Sprint Report

We had a great sprint at Logilab the other week-end, and this was by far the most productive sprint on Distutils ever. That's partially because all the core work we did in the last year starts to surface ! That's also because we had a good team of hackers, focused on specific tasks. I did not merge all the work yet but it should be done this week and an alpha released right after.

Now to the list of goodness..

Data files

We can now express data files in setup.cfg, and use a specific API to work with them. The goal is to let OS Packagers configure where those files should land at installation time, without breaking the code that uses them. The brainstorming we did last year at Pycon is here : http://hg.python.org/distutils2/file/tip/docs/design/wiki.rst and it's now a reality. This is a good step torwards a cleaner packaging system.

Setup.cfg completion

setup.cfg lacked a few things to be able to fully replace a setup.py, like defining extensions to be compiled. This is now done and we're going to maintain a page were we list all projects that were successfully converted. The page lives here for now: [https://bitbucket.org/tarek/distutils2/wiki/Deployments_using_setup.cfg][] and I will announce it widely once the alpha is released, so people can start to convert their own projects. We did convert more projects, and I need to update that page later this week.

Installer / Uninstaller

A first version that installs a project and its dependencies, as well as an uninstaller, was completed. Among other things, it will rollback the installation in case it encounters any issue. This tool exists mainly as a implementation reference to exercise all the tools that are provided in Distutils2 to browse an installation, build a depgraph or query PyPI. There's still a bit of backward compatibility work to do in order to deal with Setuptools-based installations and projects, but most things are done. I expect this to be finished and included in the alpha.

From Distutils1 to Distutils2 and vice-versa

Since setup.cfg completely replaces setup.py -- which is ignored by Distutils2, you can make your project compatible with both. This implies that you have to maintain two files that contain duplicate information, like the project name or the version. We created a tool during the sprint to avoid this: a simple function that you can use in your setup.py file to convert setup.cfg options into Distutils1 options.

Of course, to avoid adding a Distutils2 dependency into that setup.py file, we inject that function into the module, and we'll provide a command in pysetup. to generate it:
$ pysetup createD1setup

setup.py successfully created.

And if you want to do it the other way around, we offer a new feature in the wizard that will run your setup.py file and generate a setup.cfg. This is the tool we'll promote in order to make it easy for people to add Distutils2 support.

Stuff left to do

Besides the merges, before I release the next alpha there's one big task I need to do: remove the fancygetopt.py file, a layer on the top of getopt, and add a simpler, isolated module to process the command line. This will clean up a lot the code base, and make the dist.py module stop dealing directly with this. It will only implement the Distribution class, and consume command line options without having to be the one that generates them.

I am not sure yet what I'll use, since both optparse and argparse are unable to meet my requirements here. A custom command-line parser is not the best thing to maintain though..

Thank you Logilab & Bearstech

Logilab is awesome. We had many people from their teams sprinting with us, and they paid our meals every day and covered Alexis' travel costs. Bearstech was awesome as well, as they covered several snacks expenses.

Thanks to all sprinters that made it there, or worked online. We should do these more often.