Not possible to set default display manager in Kubuntu Hardy Alpha 4

Thanks for taking the time to report this issue, to help diagnose this can you please provide the output of:
cat /etc/X11/default-display-manager

For reasons unrelated to this bug report, I am sending this message from a gutsy session. (See my bug reports Bug 190378 and Bug 190381)

bruce@Xenophon:~$ cat /media/hardy/etc/X11/default-display-manager
/usr/bin/kdm-kde4
bruce@Xenophon:~$

You should have been able to change that to kdm or kdm-kde4 (the real path) from "sudo dpkg-reconfigure kdm" or "sudo dpkg-reconfigure kdm-kde4".
I set my /etc/X11/default-display-manager to the same value as you have and "sudo dpkg-reconfigure kdm-kde4" allowed me to change it to kdm or kdm-kde4

When you get back to your Gutsy session please edit /var/lib/dpkg/info/kdm-kde4.config and change line 8: "set -e to:
"set -ex"
Then re-run "sudo dpkg-reconfigure kdm-kde4" and post the output from the console after you've chosen kdm or kdm-kde4.

No joy. :-(

I reconfigured kdm-kde4 as you directed after editing the config file. Console output is attached.

You don't seem to have attached anything

This would appear to be a bug in Launchpad. The copy of the e-mail in my "Sent" folder has the attachment. Will upload it directly, using the Web interface.

> You don't seem to have attached anything

Re-send of attachment, as promised

Can you also post the output when you select "kdm" instead of "kdm-kde4"
As a workaround you should be able to do "echo /usr/bin/kdm | sudo tee /etc/X11/default-display-manager" to set kdm as the default, then "sudo /etc/init.d/kdm start" should work.

Interesting results: after your earlier message where I had edited the config file, I had tried to reconfigure only kdm-kde4. That produced no results. Selecting kdm allowed the login manager to load. Since then, I have successfully switched between kdm and kdm-kde4.

The problem seems to have been that "/usr/bin/kdm-kde4" was in /etc/X11/default-display-manager, which neither matched the kdm-kde4 daemon ("/usr/lib/kde4/bin/kdm") nor the kdm one ("/usr/bin/kdm").
I've found another, related problem though: only using "sudo dpkg-reconfigure kdm-kde4" I was unable to change the login manager from kdm-kde4 back to kdm.
I'm attaching a patch to fix this.

This bug was fixed in the package kdebase-workspace - 4:4.0.2-0ubuntu2

---------------
kdebase-workspace (4:4.0.2-0ubuntu2) hardy; urgency=low

  * debian/kdm-kde4.config: merged from kdm package, fixes reconfiguration for
    kdm/kdm-kde4 (LP: #190375)

 -- Daniel Hahler <email address hidden> Tue, 11 Mar 2008 17:44:08 +0000