All singing all dancing Python 3

[warsaw]

I think dirtbike should be pure unadulterated Python 3, with 3.4 as a minimum requirement. All mod cons! What do you think?

[paulproteus]

I think that's fine with me! What I'd like to see then is:

• README indicating as much, and
• Test suite updated accordingly.

[warsaw]

I'm inclined to use tox and nose2 for testing. nose2 has a great test runner and tox will keep us honest with Python 3.4 and 3.5 (and future Python 3's). I have a lot of experience with them and like them a lot. If you're cool with that, I'll look at converting tests.sh.

[paulproteus]

Fine with me!​

[paulproteus]

Note also my ridiculous undocumented hacks in .travis.yml to turn Ubuntu 12.04 into (basically) Debian jessie, which serves as the source of a package to test against (python-six, chosen solely for simplicity).

Do we need to be able to convert installed Python 2.7 packages into wheels, too? If so, we should think this through I suppose.

[paulproteus]

The intended purpose of this tool is to support the python-pip package in Ubuntu & Debian, so I'm inclined to do whatever best serves that purpose.

[paulproteus]

So long a python-pip dependency is polyglot Python 2.7/Python 3, we could mark the wheel as compatible with Py27 and Py34 for now.

Also I suppose we're probably going to use zipimport rather than any real wheel machinery, so that sort of metadata probably doesn't matter.

[warsaw]

That's a good point. Yes, I think we'll need to be able to rewheel Python 2.7 packages too, which might be problematic given that we're using pkg_resources.get_distribution() to calculate the package, and that will return different answers under Python 2 and 3. Hmm. I'd rather not have a dirtbike-2 and dirtbike-3 scripts, preferring dirtbike -2 or dirtbike -3 (with probably -3 as the default?). Indeed, more thought and testing will be required. But either way, it shouldn't affect nosytoxing things, so on to that first!

[dstufft]

FWIW pip doesn't accept any dependencies that don't work single source Python 2 and Python 3. If there's a dependency with something Python version specific it'll be something Debian added as far as I can think of.

[warsaw]

Now that we have refactored strategy classes for getting the installed list of files, I think it's more possible to make dirtbike itself Python 3, and implement a call-out for Python 2. That's if we want to support anything but universal wheels, which perhaps we don't.

[dstufft]

Assuming dirtbike is only going to be used for pip then universal wheels is all you'll ever need. Pip's bundling policy does not allow anything else.

[paulproteus]

I'm vaguely +1 on narrowing the scope to make implementation easier, fwiw.