kern/66021: -current system mount is broken: mount: exec mount_ufs2 not found

[Daniel Lang]

>Number:         66021
>Category:       kern
>Synopsis:       -current system mount is broken: mount: exec mount_ufs2 not found
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Apr 27 02:40:14 PDT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Daniel Lang <dl at leo.org>
>Release:        FreeBSD 5.2-CURRENT
>Organization:
TU Muenchen
>Environment:
System: FreeBSD 5.2-CURRENT FreeBSD 5.2-CURRENT #21: Tue Apr 27  09:59:27 CEST 2004 root at laprbg8.informatik.tu-muenchen.de:/usr/obj/usr/src/sys/BATLETH i386

>Description:

After updating -CURRENT, I installed kernel and booted in single-user.
After seeding random and running mergemaster -p (as suggested by 
UPDATING), the system did not allow to remount / with the
error-message as above. 

However, root seems to be mounted read-write already, since 
I could run mergmaster and update the master.passwd.

I read the archives and stumbled across this error, and now I am
afraid to follow-through with the update, in case the system will
then be broken. The error-messages suggest that it is not impossible
to create an broken system, thus I did not yet installed world.
Especially the new "mount" binary in /usr/obj/usr/src/sbin/mount/
shows the same problem, and there is no 'mount_ufs2' binary anywhere
(of course not).

>How-To-Repeat:

Update your -current to Tue Apr 27  09:59:27 CEST, build world and kernel,
install kernel, boot in single-user, try to remount /

>Fix:

  unknown.


>Release-Note:
>Audit-Trail:
>Unformatted: