dev-java/swt uses pkg-config - in the ebuild (if xulrunner flag is enabled), and during build If pkg-config is not installed, it bails out, with for example this error: [...] i686-pc-linux-gnu-gcc -march=native -O2 -pipe -fomit-frame-pointer -DSWT_VERSION=3448 -DLINUX -DGTK -I/opt/sun-jdk-1.6.0.13/include -I/opt/sun-jdk-1.6.0.13/include/linux -fPIC `pkg-config --cflags gtk+-2.0` -c os.c /bin/sh: pkg-config: not found In file included from os_structs.h:16, from os.c:17: os.h:27:21: error: gtk/gtk.h: No such file or directory os.h:28:21: error: gdk/gdk.h: No such file or directory os.h:29:25: error: pango/pango.h: No such file or directory os.h:30:30: error: pango/pango-font.h: No such file or directory In file included from os.c:17: os_structs.h:20: error: expected '=', ',', ';', 'asm' or '__attribute__' before '*' token [... here it goes on with errors due to missing headers ...] I would guess, that it is the case for all swt-versions in the tree :) Solution: Add "dev-util/pkgconfig" to DEPEND
pkgconfig dep added