-extra_cflags = -I./lib `pkg-config --cflags glib-2.0 gmime-2.4 talloc`
-extra_cxxflags = `xapian-config --cxxflags`
+extra_cflags := $(shell pkg-config --cflags glib-2.0 gmime-2.4 talloc)
+extra_cxxflags := $(shell xapian-config --cxxflags)
+
+emacs_lispdir := $(shell pkg-config emacs --variable sitepkglispdir)
+emacs_startdir := $(shell pkg-config emacs --variable sitestartdir)