You do know that this is directly supported by pkg_comp(8), don't you ?

You just have to specify a value for NETBSD_RELEASE in pkg_comp's config
file.
:;grep NETBSD_RELEASE /home/seb/pkg_comp/162.conf 
NETBSD_RELEASE="1.6.2"
:;uname -srm
NetBSD 2.0G i386
:;priv pkg_comp -c 162 chroot            
PKG_COMP ==> Installing new `pkg-vulnerabilities' file
PKG_COMP ==> Mounting sandboxed filesystems
PKG_COMP ==> Entering sandbox `/u/pkg_comp/162'
pkg_comp:162.conf# uname -srm
NetBSD 1.6.2 i386
pkg_comp:162.conf# 
PKG_COMP ==> Unmounting sandboxed filesystems
:;

pkg_comp(8) stuff LD_PRELOAD into CHROOT/etc/{shrc,csh.login,csh.cshrc}.

Also beware that this break some package's build as LD_PRELOAD is thus set
in the environment for running emulation binaries... Think about Linux's
ld.so which supports LD_PRELOAD: it fails to load libkver.so of course.

On Mon, Oct 04, 2004 at 02:59:14AM +0200, Hubert Feyrer wrote:
> On Sat, 2 Oct 2004, grant beattie wrote:
> >that should do it :)
> 
> Indeed, seems to work pretty well, assuming nothing resets $ENV even the 
> config symlink is not needed. So some more detailled steps seems to be:
> 
>  * install pkgsrc/pkgtools/libkver
> 
>    # cd /usr/pkgsrc/pkgtools/libkver
>    # make install
> 
>  * Make sure the libkver shared object is available both in the sandbox
>    and in the "real" (outside) system:
> 
>    # mkdir -p /usr/sandbox/usr/local/lib
>    # cp /usr/pkg/lib/libkver.so /usr/local/lib
>    # cp /usr/pkg/lib/libkver.so /usr/sandbox/usr/local/lib
> 
>  * Start the build (e.g. for NetBSD 3.0 pkgs):
> 
>    # cd /usr/sandbox/usr/pkgsrc
>    # env LD_PRELOAD=/usr/local/lib/libkver.so \
> 	 LIBKVER_OSRELEASE=3.0 \
> 	 sh mk/bulk/do-sandbox-build
> 
> Maybe someone wants to test this before we put it into (the successor of) 
> Packages.txt?
> 
> 
>  - Hubert
> 
> -- 
>                         ,,__
> If wishes were wings,  o"   )~  would fly.            -- Go www.NetBSD.org!
>                         ''''