The Help file lists a number of parameters for the ClarionCL command line utility. Here's one that appears to be undocumented, and was passed along to me by Ilka Ferrett.
The /p parameter lets you pass compiler settings, which in this example will set debug info (vid) to min and turn on line numbers.
/p:vid=min;line_numbers=True
If you have any other ClarionCL tips, please post them here!