@GeekAndDad it's definitely the same character - I thought the same thing so I copied it straight from the file. There's no other invisible characters (turned on invisible chars in BBEdit).
Can't escape it like that, compiler yells (as it should)
its so weird.
fun new clue: changing the separator to just “=" crashes with the error "Swift/ContiguousArrayBuffer.swift:600: Fatal error: Index out of range”
Also, this is Swift running as a command line script (i.e. with hash bang on first line)