Error found:
in module MissingRecordField
at tests/purs/failing/MissingRecordField.purs:10:19 - 10:23 (line 10, column 19 - line 10, column 23)

  Type of expression lacks required label age.

while checking that type { first :: String
                         , last :: String 
                         }                
  is at least as general as type { age :: Number
                                 | t0           
                                 }              
while checking that expression john
  has type { age :: Number
           | t0           
           }              
in value declaration result

where t0 is an unknown type

See https://github.com/purescript/documentation/blob/master/errors/PropertyIsMissing.md for more information,
or to contribute content related to this error.