XO0423: a format's wire string given twice

A field may override its shared wire name (as "name") once per format, with json "...", sql "...", or xml "...". Two strings for the same format leave its name ambiguous. Keep one. See core 2.2 and decision 0315.

Example

struct User {
  id json "id" json "ID": Int
} derive Json

Fix

struct User {
  id json "ID": Int
} derive Json

Run xo explain XO0423 for this text in a terminal, or see section 10.6 of the specification.