bug#65720: Guile-Git-managed checkouts grow way too much

["Ludovic Courtès" <ludo@gnu.org>]

Hello!

Josselin Poiret <dev@jpoiret.xyz> skribis:

> Right, although I wouldn't necessarily say that the former doesn't have
> a proper API, but rather that it has a Unix-oriented API.  That leads to
> performance issues on e.g. Windows but on Linux I'm not sure there's
> much of a difference.

[...]

> We could consider replacing the guile-git dependency with another
> library built directly on top of git-minimal, and have this be a
> dependency of Guix.  Not ideal though, and not really scalable either:
> we can't just add every VCS as direct dependencies.

I cannot imagine a viable implementation of things like ‘commit-closure’
and ‘commit-relation’ from (guix git) done by shelling out to ‘git’.
I’m quite confident this would be slow and brittle.

It looks like there’s no option other than carrying the two
implementations.

~~~

Years ago, Andy Wingo sketched a plan for GNU hackers to implement Git
in pure Scheme.  That was on April 1st though, so people mistakenly
assumed it was a joke and the project was never carried out.

I digress, but I wonder: is there not even a viable Haskell or OCaml
implementation of Git?

Thanks,
Ludo’.