[N1QL] intersect/except queries throw internal execution errors

This behavior is NOT seen in 6.5.0-2988 and IS seen in 6.5.0-3013.

Repro:
load travel-sample
execute this query
select type from `travel-sample` intersect select type from `travel-sample` s where s.stops>2

you get this error:
[

{ "code": 5002, "msg": "Execution internal error: consumer input is nil" }

]

Explain:
{
"#operator": "IntersectAll",
"first": {
"#operator": "Sequence",
"~children": [
{
"#operator": "PrimaryScan3",
"index": "#primary",
"index_projection":

{ "primary_key": true }

,
"keyspace": "travel-sample",
"namespace": "default",
"using": "gsi"
},

{ "#operator": "Fetch", "keyspace": "travel-sample", "namespace": "default" }

,
{
"#operator": "Parallel",
"~child": {
"#operator": "Sequence",
"~children": [
{
"#operator": "InitialProject",
"result_terms": [

{ "expr": "(`travel-sample`.`type`)" }

]
},

{ "#operator": "Distinct" }

,

{ "#operator": "FinalProject" }

]
}
},

{ "#operator": "Distinct" }

]
},
"second": {
"#operator": "Sequence",
"~children": [
{
"#operator": "PrimaryScan3",
"as": "s",
"index": "#primary",
"index_projection":

{ "primary_key": true }

,
"keyspace": "travel-sample",
"namespace": "default",
"using": "gsi"
},

{ "#operator": "Fetch", "as": "s", "keyspace": "travel-sample", "namespace": "default" }

,
{
"#operator": "Parallel",
"~child": {
"#operator": "Sequence",
"~children": [

{ "#operator": "Filter", "condition": "(2 < (`s`.`stops`))" }

,
{
"#operator": "InitialProject",
"result_terms": [

{ "expr": "(`s`.`type`)" }

]
},

{ "#operator": "Distinct" }

,

{ "#operator": "FinalProject" }

]
}
},

{ "#operator": "Distinct" }

]
}
}