Re: git add --all does not respect submodule.<name>.ignore

[Stefan Beller <sbeller@google.com>]

On Tue, Jan 30, 2018 at 12:25 PM, Michael Scott-Nelson
<mscottnelson@gmail.com> wrote:
> Giving a submodule "ignore=all" or "ignore=dirty" in .gitmodule
> successfully removes that module from `git status` queries. However,
> these same diffs are automatically added by git-add, eg `git add .` or
> `git add --all` adds the submodules that we want ignored. This seems
> inconsistent and confusing.

My prime suspect for this change would be
https://github.com/git/git/commit/5556808690ea245708fb80383be5c1afee2fb3eb

> Workflow reason:
> We want to be able to have supers and subs checked-out, make changes
> to both, but only update the SHA-1 pointer from super to sub when
> explicitly forced to do so, eg `git add -f subName`. This workflow
> prevents continuous merge conflicts from clashing SHA-1 pointers while
> still allowing `git add --all`, allowing a sort of middle ground
> between submodules and an untracked library.

For that you want to set the ignore flag locally in .git/config instead of
.gitmodules. The .gitmodules seems like a convenient place to "share
submodule config", but that is a slippery slope and I think that was a
mistake by the project.

(If you control the environment, you could also put the ignore flags into
the system wide config)

> Teaching git-add about submodule.ignore and/or teaching .gitignore
> about submodules would be awesome.

I wonder if we can address this issue with even more config options.
(sounds bad, but is the first thought I have)

> Also experimented with `git update-index --assume-unchanged subName`,
> but I believe that it does not get committed and besides also does not
> seem to have a way to `git add -f`.

The assume-unchanged bit is a performance optimisation for powerusers,
but its documentation words it in a less dangerous way, such that it sounds
as if it is a UX feature instead of a performance thing. I'd stay away from
that know.

Stefan