Command line parameter overrides incorrectly parsed

[qikaigu]

The command line parameters cannot be correctly parsed when using overrides with whitespace (--key value).

For example, the following command yields Cannot find key error:
fromconfig config.yaml --params.random_state 123 --output /tmp - run

ERROR: Cannot find key: /tmp
Usage: fromconfig <group|value>
  available groups:      params
  available values:      run | output