Installworld deletes libc

[Jason C. Wells]

I have the problem similar to one described in 20071024 UPDATING.  The 
build is running inside a jail. The system is 6.2-RELEASE. I supped this 
moring.  I have the correct lib/Makefile.  During installworld I receive 
an error:

install: /lib/libc.so.6: chflags: Operation not permitted
*** Error code 71

Stop in /usr/src/lib/libc.

My situation is different in the libc is erased in the process.  Copying 
the new libc.so.6 from /usr/obj does not fix the problem.

Any ideas?

Thanks,
Jason