5.3R cvsup failure, libm.so.2. COMPAT files missing?

[dev tree]

I did a fresh install of 5.3-R AMD64 from the disc1 dated
Nov 05 (I verified the md5 checksum), selecting "ALL"
under Distributions.  I added package cvsup-16.1h,
did a buildworld and an SMP kernel, then attempted to do
a cvsup update along the RELENG5_3 line.

I got the following error on a missing library file:

   inoxidable[34]#	uname -a
   FreeBSD inoxidable.tex-an.net 5.3-RELEASE FreeBSD 5.3-RELEASE #0:
   Wed Dec 15 13:31:38 UTC 2004
   root at inoxidable.tex-an.net:/usr/obj/usr/src/sys/SMP  amd64
   inoxidable[35]#
   inoxidable[35]#	cd /usr/src
   inoxidable[36]#
   inoxidable[36]#	make update
   --------------------------------------------------------------
   >>> Running /usr/local/bin/cvsup
   --------------------------------------------------------------
   /libexec/ld-elf.so.1: Shared object "libm.so.2" not found, required by
   "cvsup"
   *** Error code 1

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

   Stop in /usr/src.
   inoxidable[37]#


Checking to see if there is such a file somewhere on a different
5.3-R amd64 system:

   rc[108]# locate libm.so.2
   /usr/src/lib/compat/compat22/libm.so.2.0.gz.uu
   /usr/src/lib/compat/compat4x.alpha/libm.so.2.bz2.uu
   /usr/src/lib/compat/compat4x.i386/libm.so.2.bz2.uu
   rc[109]#

Checking a 5.3-R i386 box to see what it has:

   coin[101]#
   coin[101]# uname -a
   FreeBSD coin.capnet.state.tx.us 5.3-RELEASE FreeBSD 5.3-RELEASE #0: Fri
   Nov  5 04:19:18 UTC 2004
   root at harlow.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
   coin[102]#
   coin[102]# locate libm.so.2
   /usr/lib/compat/aout/libm.so.2.0
   /usr/lib/compat/libm.so.2
   /usr/src/lib/compat/compat22/libm.so.2.0.gz.uu
   /usr/src/lib/compat/compat4x.alpha/libm.so.2.bz2.uu
   /usr/src/lib/compat/compat4x.i386/libm.so.2.bz2.uu
   coin[103]#
   coin[103]# exit
   exit

It looked like a COMPAT file, so I did a whole new buildworld, etc,
with the COMPAT items un-commented in make.conf, but that did
not result in a libm.so.2, nor actually any files at all
in the /usr/lib/compat area.

   inoxidable[34]# locate libm.so.2
   /usr/src/lib/compat/compat22/libm.so.2.0.gz.uu
   /usr/src/lib/compat/compat4x.alpha/libm.so.2.bz2.uu
   /usr/src/lib/compat/compat4x.i386/libm.so.2.bz2.uu
   inoxidable[35]#
   inoxidable[35]# ls -alF /usr/lib/compat
   total 14
   drwxr-xr-x  3 root  wheel   512 Dec 14 17:45 ./
   drwxr-xr-x  4 root  wheel  8704 Dec 15 15:31 ../
   drwxr-xr-x  2 root  wheel   512 Nov  5 02:41 aout/
   inoxidable[36]#
   inoxidable[36]# ls -alF /usr/lib/compat/aout
   total 4
   drwxr-xr-x  2 root  wheel  512 Nov  5 02:41 ./
   drwxr-xr-x  3 root  wheel  512 Dec 14 17:45 ../
   inoxidable[37]#


What did I do wrong, or how do I get cvsup to work in 5.3R on AMD64?
If it's a known problem, then it's probably fixed by now, but my
way of fixing such things is to do a make update, so you can see
why I'm stuck.

Let me know if I've left out any important information.