-- in.cue --
r: {
	a?: 3
	b:  a      @test(err, code=incomplete, contains="cannot reference optional field: a", pos=[0:6])
	c:  r["a"] @test(err, code=incomplete, contains="cannot reference optional field: a", pos=[0:8])
}
-- out/errors.txt --
[incomplete] r.b: cannot reference optional field: a:
    ./in.cue:3:6
[incomplete] r.c: cannot reference optional field: a:
    ./in.cue:4:8
-- out/eval/stats --
Leaks:  0
Freed:  5
Reused: 0
Allocs: 5
Retain: 0

Unifications: 5
Conjuncts:    5
Disjuncts:    0
