On Mon, Sep 17, 2018 at 09:52:48PM +0000, Joseph Myers wrote: > On Wed, 12 Sep 2018, Mao Han wrote: > > > +ifeq ($(subdir),debug) > > +CFLAGS-backtrace.c += -funwind-tables > > +endif > > This is in the generic debug/Makefile, so you shouldn't need it here. OK. I'll remove it. Thanks Han Mao