libudev must be linked there too.
OBJS = main.o
CFLAGS += -I$(multipathdir) -I$(mpathpersistdir)
-LDFLAGS += -lpthread -ldevmapper -L$(mpathpersistdir) -lmpathpersist -L$(multipathdir) -lmultipath
+LDFLAGS += -lpthread -ldevmapper -L$(mpathpersistdir) -lmpathpersist -L$(multipathdir) -lmultipath -ludev
EXEC = mpathpersist
OBJS = main.o
CFLAGS += -I$(multipathdir)
-LDFLAGS += -lpthread -ldevmapper -ldl -L$(multipathdir) -lmultipath
+LDFLAGS += -lpthread -ldevmapper -ldl -L$(multipathdir) -lmultipath -ludev
EXEC = multipath