sub-commands doing unexpected things

[cheradenine]

I hope I'm doing something wrong.

I compiled the code from the example under sub-commands:
https://www.bfgroup.xyz/Lyra/lyra.html#_sub_commands

If I run the program (called sub) with no arguments:
sub
result: no output

If I run the program with the run command but don't specify required arguments:
sub run

result:
Unrecognized argument 'run' while parsing: kill

In my program I have an optional argument but passing in any other arguments do not produce an error. I think that the parser fails one subcommand and then tries another?

To simulate something like this I removed the required process_name argument from the kill command and ran:
sub kill -x

result:

KILL: signal=9 process=
Unrecognized argument '-x' while parsing: run