function symbol 'void foo(const enum Colour&)' {_Z3fooRK6Colour} changed
  type 'void(const enum Colour&)' changed
    parameter 1 type 'const enum Colour&' changed
      referred-to type 'const enum Colour' changed
        underlying type 'enum Colour' changed
          underlying type changed from 'unsigned int' to 'unsigned char'

exit code 4