Seed depends on gnome-js-common (build-time), and gnome-js-common[seed] depends
on seed (build-time). The gnome-js-common build-time dep is purely to find out
the gnome-js-common module directory and append to the search path of the
Seed.js extension. However, that's a runtime dep...

---
--- configure.ac
+++ configure.ac
@@ -89,8 +89,13 @@
 AC_SUBST(GOBJECT_INTROSPECTION_LDFLAGS)
 
 dnl ========================GNOME-js common====================================
-PKG_CHECK_MODULES(GNOME_JS, gnome-js-common)
-GNOME_JS_DIR=`pkg-config --variable=moduledir gnome-js-common`
+PKG_CHECK_MODULES(GNOME_JS, gnome-js-common, have_gnome_js=yes, have_gnome_js=no)
+if test x"$have_gnome_js" = x"yes"; then
+	GNOME_JS_DIR=`pkg-config --variable=moduledir gnome-js-common`
+else
+	dnl If we don't have it installed, avoid circular build dependency
+	GNOME_JS_DIR="$libdir/gnome-js"
+fi
 AC_SUBST(GNOME_JS_DIR)
 
 dnl =============================Modules=======================================