Eli Zaretskii <eliz@gnu.org> writes:

>> From: Thierry Volpiatto <thievol@posteo.net>
>> Cc: akrl@sdf.org, psainty@orcon.net.nz, 46790@debbugs.gnu.org
>> Date: Sat, 24 Apr 2021 13:58:06 +0000
>> 
>> > I installed some change that might fix the problem.  If not, I'm
>> > afraid someone else who is smarter than I am will have to investigate
>> > this.  Thank you for your time and help.
>> 
>> Just tried and it still the same.
>
> Thanks for trying.
>
>> Probably we should start back from where it was working for me with my
>> symlink workaround and see why it was working like this and not now?
>
> Can you show the full "ln -s" command which created that symlink?

So lets restart from beginning:

I rebuilded emacs starting at b064ddd3f60 and trying to copy a file
with dired-async, it fails with error in process buffer "*emacs*" with:

emacs:
/usr/local/sbin/emacs-28.0.50/../native-lisp/28.0.50-2f134e58/preloaded/window-0d1b8b93-581f9fcd.eln:
cannot open shared object file: No such file or directory

Then I do the symlink (here from /usr/local/sbin/ directory):

sudo ln -s /usr/local/lib/emacs/28.0.50/native-lisp/ .

And now I can copy a file from dired-async with no error even without
restarting emacs. If you want to reproduce you can bypass dired-async
and use something like this much simpler which avoid possible errors
from something else and need no configuration:

    (async-start
     (lambda ()
       (copy-file "~/.emacs.d/init.el" "~/tmp/")))

you should have now a buffer "*emacs*" with same contents as above.

then make the symlink as described above and run the same snippet, you
should see your init file copied.

Hope that helps.

-- 
Thierry