crystal make errors

Error in ./main.cr:51: instantiating 'Polish::CLI:Class#run()'

Polish::CLI.run
            ^~~

in ./main.cr:14: instantiating 'Polish::CLI#run()'

    new.run
        ^~~

in ./main.cr:34: instantiating 'parse!()'

    parse!
    ^~~~~~

in ./main.cr:18: instantiating 'OptionParser:Class#parse!()'

    OptionParser.parse! do |parser|
                 ^~~~~~

in /usr/local/Cellar/crystal-lang/0.16.0/src/option_parser.cr:56: instantiating 'parse(Array(String))'

    parse(ARGV) { |parser| yield parser }
    ^~~~~

in /usr/local/Cellar/crystal-lang/0.16.0/src/option_parser.cr:56: instantiating 'parse(Array(String))'

    parse(ARGV) { |parser| yield parser }
    ^~~~~

in ./main.cr:18: instantiating 'OptionParser:Class#parse!()'

    OptionParser.parse! do |parser|
                 ^~~~~~

in ./main.cr:24: instantiating 'Polish::CLI#debug=(Bool)'

        self.debug = true
             ^~~~~

in macro 'setter' /usr/local/Cellar/crystal-lang/0.16.0/src/object.cr:414, line 3:

  1.     
  2.       
  3.         def debug=(@debug)
  4.         end
  5.       
  6.     
  7.       
  8.         def file_name=(@file_name)
  9.         end
 10.       
 11.     
 12.   

        def debug=(@debug)
                   ^~~~~~

Can't infer the type of instance variable '@debug' of Polish::CLI (did you mean @debud?)

The type of a instance variable, if not declared explicitly with
`@debug : Type`, is inferred from assignments to it across
the whole program.

The assignments must look like this:

  1. `@debug = 1` (or other literals), inferred to the literal's type
  2. `@debug = Type.new`, type is inferred to be Type
  3. `@debug = Type.method`, where `method` has a return type
     annotation, type is inferred from it
  4. `@debug = arg`, with 'arg' being a method argument with a
     type restriction 'Type', type is inferred to be Type
  5. `@debug = arg`, with 'arg' being a method argument with a
     default value, type is inferred using rules 1, 2 and 3 from it
  6. `@debug = uninitialized Type`, type is inferred to be Type
  7. `@debug = LibSome.func`, and `LibSome` is a `lib`, type
     is inferred from that fun.
  8. `LibSome.func(out @debug)`, and `LibSome` is a `lib`, type
     is inferred from that fun argument.

Other assignments have no effect on its type.

Can't infer the type of instance variable '@debug' of Polish::CLI (did you mean @debud?)