"possibly not a distinct set" error when wrapping fts::search in a for expression and converting to a free object

[scotttrinh]

• EdgeDB Version: 5.0-dev.8054+e540dec

edgedb> with result := (
.......   (for search in fts::search(default::Post, "search") union (
.......     select {
.......       object := search.object,
.......       score := search.score
.......     }
.......   ))
....... )
....... select result { text := .object.text, score := .score };

Results in the following error:

edgedb error: QueryError: possibly not a distinct set returned by an expression for a computed link 'object'
Hint: You can use assert_distinct() around the expression to turn this into a runtime assertion, or the DISTINCT operator to silently discard duplicate elements.

Adding distinct to the search.object expression does indeed work:

edgedb> with result := (
.......   (for search in fts::search(default::Post, "search") union (
.......     select {
.......       object := distinct search.object,
.......       score := search.score
.......     }
.......   ))
....... )
....... select result { text := .object.text, score := .score };
{}