sqlite3 builtin.mk

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

pkgsrc now contains a builtin.mk for sqlite3, since that library was imported 
to NetBSD recently.

It doesn't work though. It detects the builtin sqlite3 correctly but then 
pkg-config does not find the sqlite3.pc file.

This is, IIUC, caused by the the following:
a) for builtin packages, nothing is linked into work/.buildlink because the 
compiler will find the stuff anyway
b) pkg-config however has a fixed path set
/usr/pkgsrc/mk/tools/pkg-config.mk:_PKG_CONFIG_LIBDIR?=${BUILDLINK_DIR}/lib/pkgconfig:${BUILDLINK_DIR}/share/pkgconfig

I see three possible solutions:
1) make builtin packages also link their files into work/.buildlink -- for 
this, we need to create PLISTs for the builtin stuff, so buildlink knows what 
to link there; on the other hand, if pursued to extremes, will give us the 
option to disallow access to /usr to the compiler and hardwire the dependencies 
completely (no surprises if e.g. Mac OS X grows another library in the base 
system). Much effort though, probably too much.
A partial implementation of this might only link the sqlite3.pc file where it 
can be found, but I'm not fond of that idea.

2) change the default pkg-config to include /usr/lib/pkgconfig

or

3) define a variable that builtin.mk files can set containing a path that will 
be added to _PKG_CONFIG_LIBDIR.

I guess 3) is the best solution for now.

Comments?
 Thomas