Got this warning when compiling Python on Mac:

building '_scproxy' extension
gcc -Wno-unused-result -Wsign-compare -g -O0 -Wall -Wstrict-prototypes -Werror=declaration-after-statement -I./Include -I. -IInclude -I/usr/local/include -I/Users/sky/Code/python/cpython/Include -I/Users/sky/Code/python/cpython -c /Users/sky/Code/python/cpython/Modules/_scproxy.c -o build/temp.macosx-10.9-x86_64-3.6-pydebug/Users/sky/Code/python/cpython/Modules/_scproxy.o
/Users/sky/Code/python/cpython/Modules/_scproxy.c:74:10: warning: comparison of address of 'kSCPropNetProxiesExcludeSimpleHostnames' not equal to a null pointer is
      always true [-Wtautological-pointer-compare]
    if (&kSCPropNetProxiesExcludeSimpleHostnames != NULL) {
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~    ~~~~
/System/Library/Frameworks/SystemConfiguration.framework/Headers/SCSchemaDefinitions.h:3812:17: note: expanded from macro 'kSCPropNetProxiesExcludeSimpleHostnames'
          SC_SCHEMA_KV(kSCPropNetProxiesExcludeSimpleHostnames          \
                       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/System/Library/Frameworks/SystemConfiguration.framework/Headers/SCSchemaDefinitions.h:469:31: note: expanded from macro 'SC_SCHEMA_KV'
  #define SC_SCHEMA_KV(k,v,t)   k
                                ^
1 warning generated.
gcc -bundle -undefined dynamic_lookup build/temp.macosx-10.9-x86_64-3.6-pydebug/Users/sky/Code/python/cpython/Modules/_scproxy.o -L/usr/local/lib -o build/lib.macosx-10.9-x86_64-3.6-pydebug/_scproxy.cpython-36dm-darwin.so -framework SystemConfiguration -framework CoreFoundation

I am not sure though whether the patch is correct solution. But anyway....