Enable Debugging symbols in PJPROJECT for Asterisk-11

How to enable debug symbols in pjproject’s static library included in res_rtp_asterisk.so

My res/Makefile is having below lines,

clean::
@if [ -f pjproject/build.mak ]; then $(MAKE) -C pjproject realclean; fi
rm -f snmp/.o snmp/.i ael/.o ael/.i ais/.o ais/.i

dist-clean::
rm -f pjproject/build.mak

pjproject/build.mak: pjproject/aconfigure
(cd pjproject && CFLAGS="-fPIC" ./configure --build=$(BUILD_PLATFORM) --host=$(HOST_PLATFORM) --disable-floating-point --disable-sound --disable-oss --disable-speex-aec --disable-l16-codec --disable-gsm-codec --disable-g722-codec --disable-g7221-codec --disable-speex-codec --disable-ilbc-codec --disable-g711-codec --disable-ffmpeg)

ifneq ($(findstring $(MAKECMDGOALS),all),)
-include pjproject/build.mak
endif

.PHONY: FORCE
FORCE:

$(PJ_LIB_FILES): FORCE
$(MAKE) -C $(patsubst %/lib/,%,$(dir $@))/build/ …/lib/$(notdir $@)

#ifeq ($(subst 1:0,1,$(UUID)), 1)
res_rtp_webrtcserver.o: $(PJ_LIB_FILES)
res_rtp_webrtcserver.o: _ASTCFLAGS+=-DUSE_PJPROJECT
res_rtp_webrtcserver.o: _ASTCFLAGS+=$(PJ_CFLAGS)
res_rtp_webrtcserver.so: _ASTLDFLAGS+=$(PJ_LDFLAGS)
res_rtp_webrtcserver.so: LIBS+=$(PJ_LDLIBS)
#endif

I was unable to debug the crashes happened in pjproject without debug symbols.
Please help me