udev: improved to check if we have to disable udev extras because of missing dependencies

filesystem/udev/udev.conf

@@ -19,6 +19,15 @@ fi
 
 var_append confopt ' ' "--libexecdir=$libdir/udev"
 
+# check if we have to disable udev extras
+for x in glib gperf acl libusb usbutils; do
+	if ! pkginstalled -f $x; then
+		echo_warning "Disabling udev extras ($x not installed)"
+		var_append extraconfopt ' ' '--disable-extras'
+		break
+	fi
+done
+
 if ! pkginstalled gobject-introspection; then
 	var_append extraconfopt ' ' "--disable-introspection"
 fi