Didier Verna <verna(a)inf.enst.fr> writes in xemacs-beta(a)xemacs.org:
 SL Baur <steve(a)xemacs.org> writes: [ int the 21.0 announcement
]
> The Lisp packages must be installed in
> ${prefix}/lib/xemacs/xemacs-packages and
> ${prefix}/lib/xemacs/mule-packages prior to building the XEmacs
> binary. 
 	Is this the case for 21.2 ? 
The rules are identical between 21.0 and 21.2.
 My packages are currently installed under
 gnagnagna/lib/xemacs/packages/[lisp&etc&info] (it's been like this
 for a year), and XEmacs finds them all right. 
If you mean `gnagnagna' == /inf/methany[1], then that's equivalent to what
I wrote.  The abbreviation of `packages' for `xemacs-packages' is
accepted for backwards compatibility with earlier 21.0/20.5/etc. betas.
Footnotes: 
[1]  Assuming info from your most recent submitted build reports.