Nebula crashes after running `RETURN ()--() AS p;`

[zihaozeng0021]

Configuration

Nebula Version: 2025.10.28-nightly

Operating System: WSL2 – Ubuntu 24.04.1 LTS

Installation Method: Docker

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Steps to reproduce

1. Start Nebula via Docker

docker exec -it nebula-docker-compose-console-1 sh

2. Connect with nebula-console:

nebula-console -u root -p nebula -addr graphd -port 9669

3. Run the following query:

Create a test space

CREATE SPACE IF NOT EXISTS test(partition_num=1, replica_factor=1, vid_type=FIXED_STRING(8));

Select the space

use test

Run the buggy query:

RETURN ()--() AS p

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Expected behaviour

The query should either:

• return an empty result set, or
• return a normal query error (syntax/semantic), without dropping the connection.

Actual behaviour

After running RETURN ()--() AS p, nebula-console starts a reconnect loop and fails with connection refused to graphd:9669:

(root@nebula) [(none)]> use test
Execution succeeded (time spent 1.171ms/1.487435ms)

Thu, 25 Dec 2025 05:59:40 UTC

(root@nebula) [test]> RETURN ()--() AS p;
2025/12/25 06:00:02 Loop error, failed to reconnect, failed to open transport, error: dial tcp 172.19.0.10:9669: connect: connection refused
/ #

[zihaozeng0021]

The same issue also occurs in the following queries. The root cause is likely the same, but still reported them here just in case different bugs are involved.

(root@nebula) [test]> RETURN (()--()) XOR true AS x;
2025/12/25 06:13:43 Loop error, failed to reconnect, failed to open transport, error: dial tcp 172.19.0.10:9669: connect: connection refused

(root@nebula) [test]> RETURN NOT(()--()) AS np;
2025/12/25 06:11:32 Loop error, failed to reconnect, failed to open transport, error: dial tcp 172.19.0.10:9669: connect: connection refused

(root@nebula) [test]> RETURN NOT((()--()) XOR true) AS nx;
2025/12/25 06:17:43 Loop error, failed to reconnect, failed to open transport, error: dial tcp 172.19.0.10:9669: connect: connection refused