When making changes to app.yaml (to add a plugin for instance), it is easy to include extra space, forget a dash, etc. An incorrectly formatted YAML file causes
launcher rebuild app to fail with the following error:
/merge_command.rb:45:in `merge': no implicit conversion of String into Hash
The error code and description in no way imply that there is an issue with parsing app.yaml, nor does it indicate what the problem is with the file. Googling the above error does contain a couple of support links that suggest the issue, but it is far from clear.
Could an error message be added that, at a minimum, indicated that the build tool failed to parse app.yaml, or even better, indicate what the syntax or parsing error was (e.g. “expected indentation on line 17 but found <tab>”, orsimilar)