    % scons
    scons: Reading SConscript files ...
    scons: done reading SConscript files.
    scons: Building targets ...
    cc -o hello.o -c hello.c
    cc -o hello hello.o
    scons: done building targets.
    % scons -c
    scons: Reading SConscript files ...
    scons: done reading SConscript files.
    scons: Cleaning targets ...
    Removed hello.o
    Removed hello
    scons: done cleaning targets.