positional arguments:

cache-dir

Path to scons cache directory

optional arguments:

-h, --help

show this help message and exit

--prefix-len <number>

Length of cache file name used as subdirectory prefix

--version

show program's version number and exit

Unless you specify an option, it will not be changed (if it is already set in the cache config), or changed to an appropriate default (it it is not set).