Michael Heerdegen <michael_heerdegen@web.de> writes:

> Michael Albinus <michael.albinus@gmx.de> writes:
>
>> I cannot reproduce. The following works fine:
>>
>> […]
>
> You missed the TWICE part in my last message.  Just eval the above
> twice:
>
> $ emacs -Q -l tramp --eval "(add-to-list 'file-name-handler-alist
> (cons (tramp-archive-autoload-file-name-regexp)
> #'tramp-archive-autoload-file-name-handler))" --eval
> '(file-directory-p "/home/albinus/tmp/out.tar.xz/")'\
>                     --eval "(add-to-list 'file-name-handler-alist
> (cons (tramp-archive-autoload-file-name-regexp)
> #'tramp-archive-autoload-file-name-handler))" --eval
> '(file-directory-p "/home/albinus/tmp/out.tar.xz/")'
>
> Sorry, but that's the best recipe I can offer.  And I guess something
> like this is actually happening.  AFAIU, Tramp can call
> `tramp-register-archive-file-name-handler' several times - see
> tramp-archive.el line 394:

With Emacs 27.1, I ran the test in the attached script a couple of times
and could *not* reproduce your error.