make release always fails

[Ross]

It looks that I am compiling wrong TAG, somehow.

I have RELENG_8 sup file:
*default host=cvsup3.ua.FreeBSD.org
*default base=/share/freebsd/cvsup
*default prefix=/share/freebsd/RELENG_8
*default release=cvs tag=RELENG_8
*default delete use-rel-suffix
src-all

And CVS supfile:
*default host=cvsup6.ua.freebsd.org
*default base=/share/freebsd/cvsup
*default prefix=/share/freebsd/ncvs
*default release=cvs
*default delete use-rel-suffix
src-all
ports-all
doc-all
cvsroot-all

First csup both sup-files. Then make buildworld in /usr/src (which is
symlink to /share/freebsd/RELENG_8/src). It always succeeds. Then:
cd /usr/src/release
make release RELEASETAG=RELENG_8 \
             PORTSRELEASETAG=HEAD \
             BUILDNAME=8.2-STABLE-$DATE \
             CHROOTDIR=/share/freebsd/release \
             CVSROOT=/share/freebsd/ncvs

This is always fails. Each day with different errors. I want to build
nightly snapshots (DVDs) of 8.2-STABLE, what am I doing wrong?