Gnome won't compile: cannot find -lpcre

[walt]

On Wed, 28 Nov 2007, Stephane Russell wrote:

> You were right, pcre was not a dependency, so it wasn't added in the
> buildlink process. pcre was included in the gtk2 link with a "-lpcre"
> statement, for a reason I still don't understand. I could'nt find why
> that flag is added, since nothing in gtk2 requires it, not even in the
> gtk2 pkgsrc build files...

The 'magic' is in the buildlink3 files, which are a fundamental  part of
the pkgsrc build system.

Look at x11/gtk2/buildlink3.mk, for example, and you will see
. include "../../devel/glib2/buildlink3.mk", which make sense because
glib2 is an important part of gtk2.

Between the buildlink3 system and the universally beloved libtool, you
eventually pull in /usr/pkg/lib/libglib-2.0.la, which contains this:

# Libraries that this one depends upon.
dependency_libs='-L/usr/pkg/lib -lpcre -lintl'

Trivial, really, once you've spent a decade bashing your head against
the inevitability of it all :o)

A quick and dirty way to investigate these dependencies is to do a
'bmake patch' for gtk2, which takes only a minute, and then poke
around in the work/.buildlink directory to see if libpcre shows up.
If not, you can try to work backwards from there.  The work/.work.log
can also be very helpful.