In case like ticket FS-7214 <https://freeswitch.org/jira/browse/FS-7214> very helpful compile FS without optimization. When I add flags CFLAGS and CXXFLAGS like below compilation is breaks. Addiding option "--disable-optimization" for configure script is help me. export CFLAGS="$CFLAGS -O0" export CXXFLAGS="$CXXFLAGS -O0" make[4]: Entering directory `/home/build/rpmbuild/BUILD/freeswitch-1.4.13/src/mod/languages/mod_python' CC mod_python_la-mod_python.lo In file included from /usr/include/limits.h:26:0, from /usr/lib/gcc/x86_64-redhat-linux/4.8.2/include/limits.h:168, from /usr/lib/gcc/x86_64-redhat-linux/4.8.2/include/syslimits.h:7, from /usr/lib/gcc/x86_64-redhat-linux/4.8.2/include/limits.h:34, from /usr/include/python2.7/Python.h:19, from mod_python.c:35: /usr/include/features.h:330:4: error: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Werror=cpp] # warning _FORTIFY_SOURCE requires compiling with optimization (-O) Can you suggest correct way to compile FS without optimization?