> Binary distributions from the emacs-28 branch, along with source
> archives as of the time of build and for the msys package dependencies
> are now available from the GNU alpha FTP site, here:
> 
> https://urldefense.com/v3/__https://alpha.gnu.org/gnu/emacs/pretest/windows/
> emacs-
> 28/?C=M;O=D__;!!ACWV5N9M2RV99hQ!aJ2ccv8rhQIAY4zgU1TFcNiuafd_9mWfShQdRC0g6GPX
> PgxqwyEgzjQ79cNHc605$
> 
> Thanks for any help you can provide testing these. Please use
> `report-emacs-bug', as usual, to let us know about problems you
> experience.
> 
> Dieter (in CC) and I would be grateful to be copied directly when you
> suspect the problem you are reporting is related to the packaging (vs
> with Emacs 28, more generally).

Thanks for working on this.

I immediately run into a problem with `runemacs -Q' and then loading a byte-compiled file (strings.elc, attached) compiled with Emacs 20.7.  Dunno whether the problem is Emacs 28 or your packaging.  The source file is here:

https://www.emacswiki.org/emacs/download/strings.el