ios - Core Data Relationship Mappings: Double Quotes in Value Expression are automatically turned into single quotes -

after generating mapping model core data migration, value expressions relationship mapping generated correctly except 1 value expression, arguments have single quotes (') instead of double quotes ("). results in parsing error.

this expect:

function($manager ,"destinationinstancesforentitymappingnamed:sourceinstances:" , "matchtomatch" , $source.matches) 

but how function expression generated:

function($manager ,'destinationinstancesforentitymappingnamed:sourceinstances:' , 'matchtomatch' , $source.matches) 

a specific value expression generated single quotes

when change "source fetch" option in right sidebar "use custom(...)" , enter expression manually, double quotes turned single quotes.

when change value expression directly in mapping editor table, following error message:

unable parse format string "function($manager >,"destinationinstancesforentitymappingnamed:sourceinstances:" , >"matchtomatch" , $source.matches) == 1"

when build , run migration, following error message:

2016-01-27 10:30:33.875 mapc[1431:352140] *** terminating app due >uncaught exception 'nsinvalidargumentexception', reason: 'unable parse >the format string "function($manager >,'destinationinstancesforentitymappingnamed:sourceinstances:' , >'matchtomatch' , $source.matches) == 1"'

can explain, happening , how can come around issue?

1. you need remove broken relationship
2. add new 1 empty "value expression" look here