libnyanpasu/clash-nyanpasu · warning

merge value for `{field}` is not a sequence, skipped

Error message

merge value for `{field}` is not a sequence, skipped

What it means

In splice_sequence, the merge value supplied for a field must be an array (items to prepend/append to the target field). If the overlay's merge value is not a sequence, the field is left untouched and a warning is logged.

Source

Thrown at backend/nyanpasu-config/src/runtime/executor/overlay.rs:60

            config = bare_key_merge(config, key, value);
        }
    }
    config
}

fn strip_any<'a>(key: &'a str, prefixes: &[&str]) -> Option<&'a str> {
    prefixes.iter().find_map(|prefix| key.strip_prefix(prefix))
}

fn splice_sequence(
    config: ConfigValue,
    field: &str,
    value: &ConfigValue,
    prepend: bool,
    logs: &mut Vec<StepLogEntry>,
) -> ConfigValue {
    let Some(to_merge) = value.as_array_arc() else {
        logs.push(StepLogEntry::warn(format!(
            "merge value for `{field}` is not a sequence, skipped"
        )));
        return config;
    };
    let segments = parse_dotted_path(field);
    let Some(target) = get_at(&config, &segments) else {
        logs.push(StepLogEntry::warn(format!(
            "field `{field}` not found, skipped"
        )));
        return config;
    };
    let Some(existing) = target.as_array_arc() else {
        logs.push(StepLogEntry::warn(format!(
            "field `{field}` is not a sequence, skipped"
        )));
        return config;
    };

View on GitHub (pinned to f7dbce2997)

Solutions

1. Wrap the merge value in a YAML/JSON list, even for a single item
2. Validate overlay merge values are arrays before applying
3. Check the field name in the warning to locate the offending overlay entry
4. Use `set`/override semantics instead of prepend/append if a scalar value is intended

Example fix

# before
rules:
  prepend: MATCH,DIRECT
# after
rules:
  prepend:
    - MATCH,DIRECT

fn merge_values_are_arrays(overlay: &ConfigValue) -> bool {
    overlay.as_object_arc().map_or(false, |m| m.iter().all(|(_, v)|
        v.get("prepend").map_or(true, |x| x.as_array_arc().is_some()) &&
        v.get("append").map_or(true, |x| x.as_array_arc().is_some())))
}

let Some(to_merge) = value.as_array_arc() else {
    return Err(anyhow!("merge value for `{field}` must be a sequence"));
};

When it happens

Trigger: apply_overlay → splice_sequence: the overlay entry's value for `{field}` (with prepend/append merge) is a mapping or scalar instead of a list, so value.as_array_arc() returns None.

Common situations: Overlay rule like `rules: {prepend: MATCH,DIRECT}` where the value is a string instead of a list; writing `prepend: {...}` with an object; copy-pasting a single rule without wrapping it in a list.

Related errors

• overlay document is not a mapping, skipped
• invalid remove entry, skipped
• unrecognized typed config migration state: existing {} is ne
• unsupported migration store schema version {}
• profiles.yaml failed validation: {errors:?}

AI-assisted analysis of libnyanpasu/clash-nyanpasu@f7dbce2997 (2026-09-08). Data as JSON: /api/errors/8999091ed1f57492. Report an issue: GitHub.