Re: [PATCH v4] emacs: customizable names for search buffers

[Kyle Meyer <kyle@kyleam.com>]

Jose A Ortega Ruiz writes:

> In very recent emacs (i'm using its master branch, actually), if one M-x
> describe-function RET format-spec one sees in the help buffer:
>
>      Probably introduced at or before Emacs version 27.1.
>
> that's where my misconception came from.  

I see.  If I recall correctly, that help string is generated by
searching NEWS* files for the name of interest.  While that often works
okay, in this case format-spec is first mentioned in the NEWS for 27.1:

  $ git describe
  emacs-28.0.91-28-ge4886018496
  $ git grep -c format-spec -- 'etc/NEWS*'
  etc/NEWS:5
  etc/NEWS.27:1

> I guess that's potentially good news: i don't see an emacs version
> specified in notmuch's package: is it supposed to be compatible with
> emacs < 25.3?  If not, we can just forget about the regexp branch.

Here's the last statement about the minimum Emacs version I see in
Notmuch's NEWS (for v0.31):

  The minimum supported major version of GNU Emacs is now 25.1.

The example in my last message used 25.3 because that's the closest
version to 25.1 for which I had a local working tree checked out and
built.  But, as I mentioned, format-spec has been present since Emacs
21.1.