[racket-dev] git submodule for native-library packages

A report from the junior varsity squad:

I just tried this on OS X and it worked AOK.

FWIW I've been strictly doing `git pull --ff-only upstream master` to
keep my fork's master 100% in sync with PLT's. Any experimentation or
feature requests done solely on topic branches. (Like I wrote about
here: http://www.greghendershott.com/2013/04/a-guide-for-infrequent-contributors-to-racket.html
)

I don't yet know enough about Git submodules to understand the analog
of that workflow for submodules, if any. I suspect it will be moot
because I'll probably never doink around with the kind of stuff in
native-pkgs. However if submodules start to get used more extensively
I guess I may need to learn more about submodules.


On Sat, Jul 27, 2013 at 9:10 AM, Matthew Flatt <mflatt at cs.utah.edu> wrote:
> Nothing has been split out of the current git repository, but there is
> now a "native-pkgs" git submodule for the native-library packages.
>
> If you build on Mac OS X or Windows or if you run a snapshot build,
> then you'll need to use
>
>   git pull
>   git submodule init
>   git submodule update
>
> once on each repository checkout from now on, and
>
>   git pull
>   git submodule update
>
> for updates after the first checkout.
>
> If you just `git pull' without the submodule commands, then you'll have
> an empty "native-pkgs" directory. That's fine if you're building on,
> say, Linux. If you're on Mac OS X or Windows, then the makefile should
> give you a good error message and suggest using `git submodule init'
> and `git submodule update'.
>
> If you use `git submodule update' today and forget to use it in the
> future, probably things will be fine for a long time, because
> "native-pkgs" doesn't change often. If "native-pkgs" does change and
> you forget `git submodule update', then (as I understand things) `git
> status' will tell you that there's a mismatch. The mismatch report
> might take a form that's not entirely clear, but it should be enough to
> remind you to run `git submodule update'.
>
>
> I'm still unsure that submodules are going to be useful for managing a
> kind of "main-distribution" repository with references to package
> repositories. I'm much more confident that a submodule will work for
> the native-library packages in the current build structure. The native
> libraries are already kept in a separate repository, they change
> infrequently, and almost no one has to change them. Also, the
> "native-pkgs" git submodule replaces two things that I think were just
> bad forms of `git submodule update':
>
>  * A makefile target that fires on Mac OS X and uses `git pull', which
>    is bad if you happen to be working offline.
>
>  * A note in "INSTALL.txt" that tells Windows users to manually clone a
>    particular git repository.
>
> If a git submodule does not work out for native-library packages after
> all, then should be easy to roll back, since there was no split to
> rewind. Meanwhile, we get a little experience with git submodules.
>
> _________________________
>   Racket Developers list:
>   http://lists.racket-lang.org/dev