AGE returns incorrect error message for EXISTS subquery outer variable reference

[zihaozeng0021]

Configuration

AGE Version: apache/age:latest (pulled 2025-12-07)

Operating System: WSL2 – Ubuntu 24.04.1 LTS

Installation Method: Docker

---

Steps to reproduce

1. Start AGE via Docker

docker run \
  --name age \
  -p 5455:5432 \
  -e POSTGRES_USER=postgresUser \
  -e POSTGRES_PASSWORD=postgresPW \
  -e POSTGRES_DB=postgresDB \
  -d \
  apache/age:latest

2. Connect with psql

PGPASSWORD='postgresPW' psql -h localhost -p 5455 -U postgresUser -d postgresDB

3. Run the following query

CREATE EXTENSION IF NOT EXISTS age;
LOAD 'age';
SET search_path = ag_catalog, "$user", public;

SELECT * FROM ag_catalog.create_graph('test');

SELECT *
FROM cypher('test', $$
    CREATE a=()-[:T]->(),
           p=({k:exists{return a}})-[:T]->()
    RETURN 1
$$) AS (one agtype);

---

Expected behaviour

One of the following:

• The query succeeds
• A semantic/feature-limitation error, not an internal/planner-style failure.

Actual behaviour

The query fails with:

ERROR:  could not find rte for a
LINE 4:            p=({k:exists{return a}})-[:T]->()
                                                     ^

[zihaozeng0021]

The same problem occurs in the following queries:

SELECT *
FROM cypher('test', $$
    CREATE p0=(n0), (n1{k:EXISTS{WITH p0}})
    RETURN 1
$$) AS (one agtype);

SELECT *
FROM cypher('test', $$
    CREATE ()-[r4 :T6]->(), ({k2:COUNT{WITH r4.k AS a3 UNWIND [] AS a4 WITH DISTINCT NULL AS a5}})
    RETURN 1
$$) AS (one agtype);

SELECT *
FROM cypher('test', $$
    CREATE (x), ({a1:EXISTS { RETURN COUNT(0) AS a2, keys(x) AS a4 }})
$$) AS (out agtype);

SELECT *
FROM cypher('test', $$
    CREATE x = (), ({ a0:COUNT { MATCH () WHERE CASE WHEN true THEN (x IS NULL) END RETURN 0 } })
$$) AS (out agtype);

[jrgemignani]

@zihaozeng0021 Created PR #2266 to add clarification.

[jrgemignani]

@zihaozeng0021 This is now resolved in the master branch.