Centos 6.7 final Linux localhost.localdomain 3.10.40-1.el6.elrepo.i686 i have downloaded FREESWITCH MASTER branch yesterday, cd /usr/src/freeswitch/src/mod/endpoints/mod_gsmopen/libctb-0.16/build make DEBUG=0 GPIB=0 g++ -c -o release/ctb_lib_portscan.o -DNDEBUG -D_THREAD_SAFE -pthread -O0 -I../include -MTrelease/ctb_lib_portscan.o -MF`echo release/ctb_lib_portscan.o | sed -e 's,\.o$,.d,'` -MD -MP ../src/portscan.cpp In file included from ../include/ctb-0.16/linux/serport.h:12, from ../include/ctb-0.16/serport.h:15, from ../include/ctb-0.16/ctb.h:12, from ../src/portscan.cpp:1: ../include/ctb-0.16/serportx.h: In member function ‘char* ctb::SerialPort_DCS::GetSettings()’: ../include/ctb-0.16/serportx.h:178: error: ‘_snprintf’ was not declared in this scope make: *** [release/ctb_lib_portscan.o] Error 1 any solution ?