Subject: bug#22307: wildcards dir-locals causes significant build slow-down in some cases

From: Glenn Morris <[email-masked]>
Date: Sat, 02 Sep 2017 21:10:26 -0400

Eli Zaretskii wrote:

> Having read that thread, and given the one and a half years since the
> original report, this doesn't look like a problem that should block
> the release of Emacs 26.1.

It was already reverted from the previous release branch because it
wasn't considered suitable for a release. Personally I think allowing
two dir-locals (as it is now) is just not a good idea; and it's not just
me, eg http://lists.gnu.org/archive/html/emacs-devel/2016-01/msg01581.html

Anyway, the plan was to improve it for 26:

    We can also just revert it from the release branch for the moment,
    and postpone it until emacs 26 while we settle on a preferred
    interface/implementation.

Nothing's happened since then AFAIK.
But I don't have anything else to say on the issue.