Please describe the problem:
The flags determined by 'pkgconfig -cflags' are passed as CFLAGS not CPPFLAGS to
the makefiles, meaning a boatload of -I are going to the linker phase as well as
the C compiler.

Steps to reproduce:
1. ./configure
2. make


Actual results:
During step 1:

checking TERM_CFLAGS... -DORBIT2=1 -I/usr/X11R6/include
-I/usr/X11R6/include/freetype2 -I/sw/include/glib-2.0 -I/sw/lib/glib-2.0/include
-I/sw/include/orbit-2.0 -I/sw/include/bonobo-activation-2.0
-I/sw/include/gconf/2 -I/sw/include/libbonobo-2.0 -I/sw/include/gnome-vfs-2.0
-I/sw/lib/gnome-vfs-2.0/include -I/sw/include/pango-1.0 -I/sw/include/gtk-2.0
-I/sw/include/atk-1.0 -I/sw/lib/gtk-2.0/include -I/sw/include
-I/sw/include/startup-notification-1.0 -I/sw/include/libart-2.0
-I/sw/include/libgnome-2.0 -I/sw/include/libgnomecanvas-2.0
-I/sw/include/libxml2 -I/sw/include/libbonoboui-2.0 -I/sw/include/libgnomeui-2.0
-I/sw/include/libglade-2.0  

During step 2:

/bin/sh ../libtool --tag=CC --mode=link gcc-3.3  -DORBIT2=1 -I/usr/X11R6/include
 -I/usr/X11R6/include/freetype2 -I/sw/include/glib-2.0 -I/sw/lib/glib-2.0/includ
e -I/sw/include/orbit-2.0 -I/sw/include/bonobo-activation-2.0 -I/sw/include/gcon
f/2 -I/sw/include/libbonobo-2.0 -I/sw/include/gnome-vfs-2.0 -I/sw/lib/gnome-vfs-
2.0/include -I/sw/include/pango-1.0 -I/sw/include/gtk-2.0 -I/sw/include/atk-1.0 
-I/sw/lib/gtk-2.0/include -I/sw/include -I/sw/include/startup-notification-1.0 -
I/sw/include/libart-2.0 -I/sw/include/libgnome-2.0 -I/sw/include/libgnomecanvas-
2.0 -I/sw/include/libxml2 -I/sw/include/libbonoboui-2.0 -I/sw/include/libgnomeui
-2.0 -I/sw/include/libglade-2.0   -O3 -funroll-loops -fstrict-aliasing -Wall  -L
/sw/lib -o gnome-terminal  encoding.o profile-editor.o skey-popup.o terminal.o t
erminal-accels.o terminal-profile.o terminal-screen.o terminal-widget-vte.o term
inal-window.o simple-x-font-selector.o eggaccelerators.o eggcellrendererkeys.o  
 -L/usr/X11R6/lib  -lSM -lICE -lX11  -L/usr/X11R6/lib -L/sw/lib -lglade-2.0 -lgn
omeui-2 -lbonoboui-2 -lxml2 -lpthread -lz -lgnomecanvas-2 -lgnome-2 -lpopt -lart
_lgpl_2 -lstartup-notification-1 -lvte -lncurses -lSM -lICE -lgtk-x11-2.0 -lgdk-
x11-2.0 -lXrandr -lXinerama -lXext -lXcursor -latk-1.0 -lgdk_pixbuf-2.0 -lpangox
ft-1.0 -lXft -lXrender -lpangox-1.0 -lX11 -lpangoft2-1.0 -lfontconfig -lfreetype
 -lpango-1.0 -lgobject-2.0 -lgnomevfs-2 -lbonobo-2 -lgconf-2 -lbonobo-activation
 -lORBit-2 -lm -lgmodule-2.0 -lgthread-2.0 -lglib-2.0 -lintl -liconv   skey/libs
key.la 
mkdir .libs
gcc-3.3 -DORBIT2=1 -I/usr/X11R6/include -I/usr/X11R6/include/freetype2 -I/sw/inc
lude/glib-2.0 -I/sw/lib/glib-2.0/include -I/sw/include/orbit-2.0 -I/sw/include/b
onobo-activation-2.0 -I/sw/include/gconf/2 -I/sw/include/libbonobo-2.0 -I/sw/inc
lude/gnome-vfs-2.0 -I/sw/lib/gnome-vfs-2.0/include -I/sw/include/pango-1.0 -I/sw
/include/gtk-2.0 -I/sw/include/atk-1.0 -I/sw/lib/gtk-2.0/include -I/sw/include -
I/sw/include/startup-notification-1.0 -I/sw/include/libart-2.0 -I/sw/include/lib
gnome-2.0 -I/sw/include/libgnomecanvas-2.0 -I/sw/include/libxml2 -I/sw/include/l
ibbonoboui-2.0 -I/sw/include/libgnomeui-2.0 -I/sw/include/libglade-2.0 -O3 -funr
oll-loops -fstrict-aliasing -Wall -o gnome-terminal encoding.o profile-editor.o 
skey-popup.o terminal.o terminal-accels.o terminal-profile.o terminal-screen.o t
erminal-widget-vte.o terminal-window.o simple-x-font-selector.o eggaccelerators.
o eggcellrendererkeys.o  -L/sw/lib -L/usr/X11R6/lib skey/.libs/libskey.a /sw/lib
/libglade-2.0.dylib /sw/lib/libgnomeui-2.dylib /sw/lib/libgnome-keyring.dylib /s
w/lib/libjpeg.dylib /sw/lib/libbonoboui-2.dylib /sw/lib/libgnomecanvas-2.dylib /
sw/lib/libgnome-2.dylib /sw/lib/libesd.dylib /sw/lib/libaudiofile.dylib /sw/lib/
libart_lgpl_2.dylib /sw/lib/libstartup-notification-1.dylib /sw/lib/libvte.dylib
 -lncurses -lSM -lICE /sw/lib/libgtk-x11-2.0.dylib /sw/lib/libgdk-x11-2.0.dylib 
-lXrandr -lXinerama -lXext -lXcursor /sw/lib/libatk-1.0.dylib /sw/lib/libgdk_pix
buf-2.0.dylib /sw/lib/libpangoxft-1.0.dylib -lXft -lXrender /sw/lib/libpangox-1.
0.dylib -lX11 /sw/lib/libpangoft2-1.0.dylib -lfontconfig -lfreetype /sw/lib/libp
ango-1.0.dylib /sw/lib/libgnomevfs-2.dylib /sw/lib/libxml2.dylib -ldl -lpthread 
-lz /sw/lib/libbonobo-2.dylib /sw/lib/libgconf-2.dylib /sw/lib/libbonobo-activat
ion.dylib /sw/lib/libORBitCosNaming-2.dylib /sw/lib/libORBit-2.dylib /sw/lib/lib
popt.dylib /sw/lib/libgobject-2.0.dylib -lresolv -lm /sw/lib/libgmodule-2.0.dyli
b /sw/lib/libgthread-2.0.dylib /sw/lib/libglib-2.0.dylib /sw/lib/libintl.dylib -
lc /sw/lib/libiconv.dylib


Expected results:
There's no reason to pass -I (or -D) flags when linking a bunch of .o files
together.

Does this happen every time?
Yes.

Other information:
This is with OS X 10.3.9 (darwin7.9.0/ppc), XCode-1.5 (gcc3.3).

Looks like this situation occurs in ./configure, where TERM_CFLAGS is merged
into CFLAGS instead of CPPFLAGS. This patch to configure.in:

-CFLAGS="$TERM_CFLAGS $CFLAGS"
+CPPFLAGS="$TERM_CFLAGS"

gives the more normal behavior, where TERM_CFLAGS is passed to libtool during
--mode=compile but not during --mode=link and all compiling (still) succeeds.

Or is this really a libtool bug, in that libtool should be smart enough not to
pass compiler flags to the linker? If you're really paranoid that pkg-config
--cflags might give flags that are needed by the linker as well as the compiler,
you could separate it into --cflags-only-I that go into CPPFLAGS and
--cflags-only-other that go into CFLAGS.