destdir in pkg_add(1)/pkg_delete(1)

["Johnny C. Lam" <jlam%NetBSD.org@localhost>]

Can anyone please explain how the "-P destdir" support in pkg_add(1)
and pkg_delete(1) is meant to work?  I couldn't find any existing
usage of that option in pkgsrc/mk.

Even the cross-compile logic in pkgsrc/mk uses the "-p prefix"
option to directly set the installation prefix to the full path of
"cross-destdir + prefix" and then does an additional hacky step of
directly modifying the files in ${PKG_DBDIR} to remove references
to the cross-destdir.

I suspect the destdir support was added to try to support
installing and deleting packages for the cross-destdir case, but
it doesn't seem like it's used at all within pkgsrc.

My questions are in the context of making sure the package install
and deinstall scripts correctly honor PKG_DESTDIR.

Regards,
-- 
Johnny C. Lam
jlam%NetBSD.org@localhost