experiment/try: cannot reference optional field

[TLDMain]

What version of CUE are you using (cue version)?

0.16.1

Does this issue reproduce with the latest stable release?

yes

What did you do?

@experiment(try)

({
	outer?: {
		opt?: {}
	}
	inner: {
		try {
			opt: outer?.opt? & {
				try {}
			}
		}
	}
}).inner

https://cuelang.org/play/?id=076Hu4eoYC6#w=function&i=cue&f=export&o=yaml

What did you expect to see?

{}

What did you see instead?

opt: cannot reference optional field: outer:
    -:9:9

Observations

It works as expected if we delete inner try block or use opt: outer? & instead opt: outer?.opt? &

[mvdan]

Reduced a little, and in testscript form:

exec cue export with_nested.cue
exec cue export without_nested.cue

-- with_nested.cue --
@experiment(try)

{
	foo?: foo2: {}
	bar: {
		try {
			foo?.foo2 & {
				try {}
			}
		}
	}
}.bar
-- without_nested.cue --
@experiment(try)

{
	foo?: foo2: {}
	bar: {
		try {
			foo?.foo2 & {
			}
		}
	}
}.bar

As of d11a8f8:

> exec cue export with_nested.cue
[stderr]
cannot reference optional field: foo:
    ./with_nested.cue:7:4
[exit status 1]
FAIL: repro.txtar:1: unexpected command failure
> exec cue export without_nested.cue
[stdout]
{}