:title: Mason Guide: *Runtime Arguments* Runtime/Compilation Arguments ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For an example of forwarding arguments in a call to ``mason run``, a chapel program built in mason might have a ``config const number`` that corresponds to a value used in ``MyPackage.chpl``. To try out different values at runtime, pass the values for ``number`` to ``mason run`` as follows:: mason run -- --number=100 mason run -- --number=1000 .. note:: Previous releases allowed flags meant for the compiler or chapel program to be mixed with those meant for ``mason build`` or ``mason run``, respectively. As of Chapel 1.25 and mason 0.2.0, flags not intended for ``mason`` must follow a double dash ``--`` regardless of if they conflict or not.