Try to recompile with the following command:
scons platform=x11 target=release_debug tools=yes debug_symbols=no -j 4
debug_symbols=no option that tells Scons not to include debug symbols which should result in a smaller executable, or add
separate_debug_symbols=yes if you need them for debugging purposes I suppose.
You can disable some other stuff from the build by taking a look at the output of
scons -h, I think you could turn off some modules that you don't actually need.