Well, i'm trying to compile GNOME with pkgsrc in slackware, when it goes 
compile metacity it starts compiling Xcomposite, and it give an error:

checking for compositeext >= 1.0 xfixes... Package compositeext was not 
found in the pkg-config search path. Perhaps you should add the 
directory containing `compositeext.pc' to the PKG_CONFIG_PATH 
environment variable No package 'compositeext' found
configure: error: Library requirements (compositeext >= 1.0 xfixes) not 
met; consider adjusting the PKG_CONFIG_PATH environment variable if your 
libraries are in a nonstandard prefix so pkg-config can find them.
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/x11/Xcomposite

--------

root@dagobah:/usr/pkgsrc/meta-pkgs/gnome# echo $PKG_CONFIG_PATH
/usr/pkg/lib/pkgconfig

So I go to compositeext directory, and do a bmake, happens that:

checking for xextensions fixesext... Package fixesext was not found in 
the pkg-config search path. Perhaps you should add the directory 
containing `fixesext.pc' to the PKG_CONFIG_PATH environment variable No 
package 'fixesext' found
configure: error: Library requirements (xextensions fixesext) not met; 
consider adjusting the PKG_CONFIG_PATH environment variable if your 
libraries are in a nonstandard prefix so pkg-config can find them.
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/x11/compositeext
===>
===> There was an error during the ``configure'' phase.
===> Please investigate the following for more information:
===>      * config.log
===>      * /usr/pkgsrc/x11/compositeext/work/.work.log
===>
*** Error code 1

--------

Then I do a locate fixesext and the output was:

root@dagobah:/usr/pkgsrc/x11/compositeext# locate fixesext.pc
/usr/pkgsrc/devel/GConf2-ui/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/devel/eel2/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/devel/gail/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/devel/libbonoboui/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/devel/libglade2/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/devel/libgnomeui/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/devel/libwnck/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/graphics/libgnomecanvas/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/graphics/librsvg2/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/print/libgnomeprintui/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/security/gnome-keyring/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/sysutils/nautilus/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/textproc/libcroco/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/www/gtkhtml38/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/x11/gnome-desktop/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/x11/gtk2-engines/work/.buildlink/lib/pkgconfig/fixesext.pc
/usr/pkgsrc/x11/xorg-libs/files/fixesext.pc
/usr/pkg/lib/pkgconfig/fixesext.pc

I have fixesext.pc in pkgconfig directory, and its set in 
PKG_CONFIG_PATH variable... how I fix this problem?!

Regards,
Alexandre Garcia