Re: [PATCH 2/3] config: add GIT_CONFIG_INCLUDES

[Patrick Steinhardt <ps@pks.im>]

On Mon, Jun 08, 2026 at 01:57:05PM +0000, Derrick Stolee via GitGitGadget wrote:
> From: Derrick Stolee <stolee@gmail.com>
> 
> The config keys 'include.path' and 'includeIf.*' allow users to specify
> config stored in a location outside of the typical list of config files
> (system, global, local, etc.). For example, users who accept the risk
> can specify helpful aliases via a file checked into the repo by pointing
> 'include.path' to the position of that file in the working directory.
> This is dangerous, but people do it.

Huh, I never even considered this use case. But of course, this is
possible, even though it's quite scary.

> What becomes tricky is that this modifies all Git behavior, including
> operations that are intended to be limited in activity or sandboxed in
> some way. These include directives can provide surprising changes to
> behavior, especially when expecting a specific list of allowed file
> accesses. This could lead to failed builds, for instance.
> 
> To allow for these user-desired features when they are running commands,
> add a new GIT_CONFIG_INCLUDES environment variable that disables these
> redirections of config when set to zero. This variable can be set by
> automation, such as build tooling, to avoid these strange behaviors.
> This could be considered a recommended option for tools executing Git
> commands, the same as GIT_ADVICE=0.

I don't know about this part though. I could see use cases where the
tools _should_ read the project-relative configuration. It might also be
the case that the user may want to evaluate some includes, but not all
of them.

That raises the question whether we can introduce the configuration in a
way that it allows a bit more flexibility than just "yes"/"no", like for
example an allow-list of locations that should be evaluated. But maybe
I'm overthinking this.

Patrick