Given:

let $d1 := map {"key1":"value1"}

let $d2 := map {"key2":"value2"}

return map:merge($d1, $d2)

where the two maps to be merged should have been included as sequence, but were, mistakenly, not, the function should return an error, since the second map gets evaluated as $options, but none of the $options are to be found inside.

It seems, that only a type-check is done, to assure valid $options, since, in another case, I got a [XPTY0004].

Minden jót, all the best, Alles Gute,
Andreas Mixich