checking cairo-pdf.h usability... no
checking cairo-pdf.h presence... no
checking for cairo-pdf.h... no
configure: error: 
*** Can't find cairo-pdf.h. You must build Cairo with the pdf
*** backend enabled.
*** Error code 1

Stop.
make: stopped in /export/CHROOT/usr/pkgsrc/x11/gtk2
*** Error code 1

Stop.
make: stopped in /export/CHROOT/usr/pkgsrc/x11/gtk2
*** Error code 1

Stop.
make: stopped in /export/CHROOT/usr/pkgsrc/graphics/graphviz
*** Error code 1

Stop.
make: stopped in /export/CHROOT/usr/pkgsrc/devel/doxygen
*** Error code 1

Stop.
make: stopped in /export/CHROOT/usr/pkgsrc/cross/avr-libc
modena@makoto 16:59:58/120206(..cross/avr-libc)% 

よく見たら、上の方に

Package 'gl', required by 'cairo', not found

これがあった。.. の時は gtk2 に gl が必要。
(多分自分で xorg を上げていて所為だと思うのだけれど)