bulk vs. options vs. buildlink

[d.den.brok%uni-bonn.de@localhost]

I have the following setup in a chroot (on NetBSD):

* PKG_DEFAULT_OPTIONS contains "ldap" and "kerberos";
* I didn't touch PREFER_PKGSRC or PREFER_NATIVE;
* the file pointed at by "limited_list" contains a single entry,
"print/cups".

This causes pbulk to fail building cups. From configure.log:

"ERROR: cyrus-sasl>=2.1.12 is not installed; can't buildlink files."

This is probably because buildlink takes into account dependencies
of built-in dependencies where pbulk does not, but I am not sure
at what place (and how) to fix this... 

Of course, a workaround is setting

PKG_OPTIONS.openldap-client = -sasl

but perhaps someone has a better idea?

TIA,

Dennis den Brok