[Ironpython-users] Splitting up the IronPython repo

[Jeff Hardy]

One of the big issues with working on IronPython is the size of the
git repository (specifically https://github.com/IronLanguages/main) -
git does not like really big repos, especially on Windows. Part of the
problem is that the repository includes:

* The DLR
* IronPython
* IronRuby
* Two copies of the Python stdlib
* The Ruby stdlib
* WiX
* and a bunch of reference assemblies

Even on a fast machine, 'git status' takes several seconds to return.
I believe this is because it was originally a TFS repo, which can
scale to handle bigger repos by using a bigger server. With git that
option doesn't exist - if the repo is too big, the only option is to
split it up.

I've created two repos - https://github.com/jdhardy/dlr and
https://github.com/jdhardy/ironpython-only - that contain just the DLR
and IronPython, respectively. In them, git calls are nearly
instantaneous, which makes working with it a lot less painful.

There are other advantages - the DLR can get its own release cycle and
packaging, and IP can then depend on a specific version of the DLR.
Each project has a modified version of the IronPython build system
that makes it easy to build for other platforms (iOS, Android, Win8,
etc. - they still need to ported and tested, but the builds are
easier).

I did most of the work using Mono/xbuild, so I know it works there
(except for a bug in Mono's .NET 4.5 support), but it has some errors
on Windows that I need to sort out.

Once I get my Windows box back and get some time to fix the few
remaining issues, I'll move the repos to the IronLanguages account and
use them for development of a real DLR release and IronPython 3.0. Any
more 2.7 releases will come out of the existing repo.

One downside is that copying patches between 3.0 and 2.7 is going to
be extra work, but 3.0 will solve so many problems with strings that I
think it will quickly become the more common target. In general Python
3 momentum is picking up so it's a good time (some recent
hand-wringing notwithstanding) to try and have IronPython 3 in the
right spot at the right time.

I haven't really addressed IronRuby because, for intents and purposes,
it's dead.

All of that said, if anyone has any objections I'd like to hear them.
The split repos work well for me but I'm curious if others prefer the
combined repo.

- Jeff