This doesn't look "right" to me. If the '-ldnsapi' is missing in
the pkg-config script of gtkglext (gtkglext-1.0.pc), it should
be fixed there. Please revert the test compile command to the
minimum, as this is the way other people will use to build their
programs.
Also, is the package that contains the "dnsapi" library already
mentioned int the $(PKG)_DEPS of gtkglext?
It's part of mingwrt, and there seem to be some others (winspool
comctl32 comdlg32) missing in the glib/gtk pkg-config trail.
I can see them in the Makefile.am, but my autotools-fu isn't up to
tracing this through to the final *.pc files. I *think* there should
be a PKG_CHECK_MODULES in configure.ac that eventually populates
GTK_EXTRA_LIBS, but then I get lost.
The easier way though, is just to patch the *.pc.in files. If you're
happy with that approach, I'll send through some updates for the other
missing ones.