Better debugging of test program

Fortune for rngxx's current commit: Half blessing − 半吉

Makefile

@@ -164,6 +164,8 @@ uninstall:
 	-rmdir $(DESTDIR)$(PREFIX)/include/$(PROJECT)/internal
 	-rmdir $(DESTDIR)$(PREFIX)/include/$(PROJECT)
 
-$(PROJECT)-test: lib$(PROJECT).so
+$(PROJECT)-test: LDFLAGS+= -lfmt -lstdc++
-	$(CC) $(CFLAGS) src/test/*.c -o $@ -l:$< -lfmt -Wl,-flto -Wl,-O3 $(LDFLAGS)
+$(PROJECT)-test: CFLAGS+= -Og -g
+$(PROJECT)-test: lib$(PROJECT)-debug.a
+	$(CC) $(CFLAGS) src/test/*.c -o $@ -l:$< $(LDFLAGS)
 	-valgrind ./$@