``` foo = { ref x: 5 } ``` generates a useless internal error ``` "NYI(desugar-member): s-mutable-field(srcloc(\"definitions://\", 4, 8, 34, 4, 16, 42), \"x\", a-blank, s-num(srcloc(\"definitions://\", 4, 15, 41, 4, 16, 42), 5))" ```
generates a useless internal error