error when upgrading 6.0-stable to 6.1-RELEASE

[Dave]

Hello,
    I'm trying to update a box from 6.0-p6 or 7 can't remember for sure 
which to 6.1-RELEASE. I've downloaded the source, done make buildworld, make 
buildkernel with a generic kernel, make installkernel, rebooted, done 
mergemaster -p then gone cd /usr/src and done make installworld, all without 
a problem. Well, make installworld blew up, it seems like a minor error it's 
trying to create symlinks somewhere and saying access denied as if the 
source directory doesn't exist. If anyone has any suggestions i'd appreciate 
them. The complete error is below.
Thanks.
Dave.

Script started on Mon Jul 24 19:09:02 2006
\u at make installworld
mkdir -p /tmp/install.LCTSB1I4
for prog in [ awk cap_mkdb cat chflags chmod chown  date echo egrep find 
grep install-info  ln lockf make mkdir mtree mv pwd_mkdb rm sed sh sysctl 
test true uname wc zic; do  cp `which $prog` /tmp/install.LCTSB1I4;  done
cd /usr/src; MAKEOBJDIRPREFIX=/usr/obj  MACHINE_ARCH=i386  MACHINE=i386 
CPUTYPE=pentiumpro  GROFF_BIN_PATH=/usr/obj/usr/src/tmp/legacy/usr/bin 
GROFF_FONT_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/groff_font 
GROFF_TMAC_PATH=/usr/obj/usr/src/tmp/legacy/usr/share/tmac 
PATH=/usr/obj/usr/src/tmp/legacy/usr/sbin:/usr/obj/usr/src/tmp/legacy/usr/bin:/usr/obj/usr/src/tmp/legacy/usr/games:/usr/obj/usr/src/tmp/usr/sbin:/usr/obj/usr/src/tmp/usr/bin:/usr/obj/usr/src/tmp/usr/games:/tmp/install.LCTSB1I4 
make -f Makefile.inc1 reinstall
--------------------------------------------------------------
>>> Making hierarchy
--------------------------------------------------------------
cd /usr/src; make -f Makefile.inc1 hierarchy
cd /usr/src/etc;  make distrib-dirs
mtree -eU  -f /usr/src/etc/mtree/BSD.root.dist -p /
mtree -eU  -f /usr/src/etc/mtree/BSD.var.dist -p /var
mtree -eU  -f /usr/src/etc/mtree/BSD.usr.dist -p /usr
mtree -eU  -f /usr/src/etc/mtree/BSD.include.dist  -p /usr/include
mtree -deU  -f /usr/src/etc/mtree/BIND.chroot.dist  -p /var/named
cd /; rm -f /sys; ln -s usr/src/sys sys
cd /usr/share/man/en.ISO8859-1; ln -sf ../man* .
ln: ./man1: Operation not permitted
ln: ./man1aout: Operation not permitted
ln: ./man2: Operation not permitted
ln: ./man3: Operation not permitted
ln: ./man4: Operation not permitted
ln: ./man5: Operation not permitted
ln: ./man6: Operation not permitted
ln: ./man7: Operation not permitted
ln: ./man8: Operation not permitted
ln: ./man9: Operation not permitted
*** Error code 1

Stop in /usr/src/etc.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.