TalGloz wrote: > If yes then the -lseal is added with the $(LDFLAGS) at the end of the > command. But it doesn't happen because LDFLAGS is overriden by the makefile included just after you set it. The relevant part copy-pasted from your mail: LDFLAGS = -L$(INCLUDE_SEAL_LIB) -llibseal.a -lpthread include $(PGXS) seal_diff_cpp.so: seal_diff_cpp.o $(CXX) -Wl,--no-undefined -shared -o seal_diff_cpp.so seal_diff_cpp.o $(LDFLAGS) As as solution, you could leave LDFLAGS alone and use a different variable, or include $(PGXS) first and *append* your options to LDFLAGS if your prefer. For instance (replacing -llibseal.a with -lseal while at it): SEAL_LDFLAGS = -L$(INCLUDE_SEAL_LIB) -lseal -lpthread include $(PGXS) seal_diff_cpp.so: seal_diff_cpp.o $(CXX) -Wl,--no-undefined -shared -o seal_diff_cpp.so seal_diff_cpp.o $(LDFLAGS) $(SEAL_LDFLAGS) Best regards, -- Daniel Vérité PostgreSQL-powered mailer: http://www.manitou-mail.org Twitter: @DanielVerite