[found the culprit] (was: [emacs -q versus empty .emacs file])

[Uwe Brauer]

>>> "Uwe" == Uwe Brauer <address@hidden> writes:

>>> "Eli" == Eli Zaretskii <address@hidden> writes:
   >> I don't know, because it works for me.  Did you try in "emacs -Q"?


 When I run emacs -Q it works as you say, but emacs -Q calls the one
 Ubuntu provides, which is 25, I am using a compiled git master version

So with 

 /opt/emacs27/bin/emacs -Q

The behavior of Z in dired is new in emacs 17; it does not uncompress a tgz to 
tar,
but extract the whole compressed tar, which is a different behavior.