Re: [PATCH v2] githooks: discuss Git operations in foreign repositories

>  Documentation/githooks.txt | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
> index a16e62bc8c8..62908602e7b 100644
> --- a/Documentation/githooks.txt
> +++ b/Documentation/githooks.txt
> @@ -27,6 +27,18 @@ repository. An exception are hooks triggered during a push ('pre-receive',
>  'update', 'post-receive', 'post-update', 'push-to-checkout') which are always
>  executed in $GIT_DIR.
>
> +Environment variables, such as `GIT_DIR`, `GIT_WORK_TREE`, etc., are exported
> +so that Git commands run by the hook can correctly locate the repository.  If
> +your hook needs to invoke Git commands in a foreign repository or in a
> +different working tree of the same repository, then it should clear these
> +environment variables so they do not interfere with Git operations at the
> +foreign location.  For example:
> +
> +------------
> +local_desc=$(git describe)
> +foreign_desc=$(unset $(git rev-parse --local-env-vars); git -C ../foreign-repo describe)
> +------------