This breaks : ``` ./configure CFLAGS="-O2 -pipe -march=native -Werror=implicit-function-declaration" ... checking for pthread_create... yes checking for pthread_condattr_setclock... yes checking for libevent directory... configure: WARNING: We found the libraries for libevent, but we could not find the C header files. You may need to install a devel package. configure: error: Missing headers; unable to proceed. ``` but neither this : ``` ./configure --enable-gcc-warnings ``` nor this ``` ./configure CFLAGS="-O2 -pipe -march=native" --enable-gcc-warnings ``` Shouldn't the later break too ?