SIGSEGV when a command with a nested command is assigned any cardinality after creation

[mknejp]

This only seems to emerge in the following constellation

cli.add_argument(
  lyra::command{"command", ...}
  .cardinality(n, m) // values don't seem to matter
  .add_argument(
     lyra::command{"subcommand", ...});

When invoked with exec command it prints

Program terminated with signal: SIGSEGV