Re: How to checkout a revision that contains a deleted submodule?

[Luke Diamand <luke@diamand.org>]

On Sat, 19 Sep 2020 at 10:03, Luke Diamand <luke@diamand.org> wrote:
>
> Maybe this is a FAQ, but I couldn't figure it out!
>
> I have a repo which has a couple of submodules.
>
> At some point in the past I deleted one of those submodules:
>
>     git rm sub2
>     git add -u
>     git commit -m 'Deleting sub2'
>     git push origin
>     ...
>     ... more commits and pushes...
>
> Now I go and clone the head revision. This gives me a clone which has
> nothing present in .git/modules/sub2.
>     login on some other machine
>     git clone git@my.repo:thing
>     cd thing
>     ls .git/modules
>     <sub2 not present>
>
> So when I go and checkout an old revision where sub2 is still around I get:
>     git checkout oldrevision
>     fatal: not a git repository: sub2/../.git/modules/sub2
>
> What am I doing wrong?
> What set of commands do I need to use to ensure that this will always
> do the right thing?
>
> Thanks
> Luke

Replying to myself, adding Jens who added the section below.

This is a known bug:

https://git-scm.com/docs/git-rm

> BUGS
> ----
> Each time a superproject update removes a populated submodule
> (e.g. when switching between commits before and after the removal) a
> stale submodule checkout will remain in the old location. Removing the
> old directory is only safe when it uses a gitfile, as otherwise the
> history of the submodule will be deleted too. This step will be
> obsolete when recursive submodule update has been implemented.

I'm wondering what "recursive submodule update" is. If I do:

    git submodule update --checkout --force --remote --recursive

then those stale repos are still left lying around. I guess that's a
different kind of recursive?

Thanks
Luke