builtin-grep: use external grep when we can take advantage of it

diff --git a/Documentation/git-var.txt b/Documentation/git-var.txt
index 379571eef0e3f7ee79f7b99c8e85845f5248e79e..a5b1a0dbab5e55a1c1fc2b0f8b35e234832808bb 100644 (file)
--- a/Documentation/git-var.txt
+++ b/Documentation/git-var.txt
@@ -19,7 +19,8 @@ OPTIONS
 -l::
        Cause the logical variables to be listed. In addition, all the
        variables of the git configuration file .git/config are listed
-       as well.
+       as well. (However, the configuration variables listing functionality
+       is deprecated in favor of `git-repo-config -l`.)
 
 EXAMPLE
 --------