dbt-labs/dbt-core · info

yaml deserializes into config type

Error message

yaml deserializes into config type

What it means

A test-only `.expect()` asserting that the provided YAML successfully deserializes into the config struct type `S` (e.g. `ModelConfig`) via `dbt_jinja_utils::serde::from_yaml_raw`. If the YAML in a test case is malformed or incompatible with the config type, the test panics here instead of producing a comparison failure.

Source

Thrown at crates/dbt-parser/src/dbt_project_config.rs:1343

    {
        // Diagnostics are emitted through the tracing layer, so capture them with a
        // test consumer rather than a status reporter.
        let (test_layer, _, _, log_records) = TestLayer::new();
        let subscriber = create_tracing_subcriber_with_layer(
            tracing::level_filters::LevelFilter::TRACE,
            test_data_layer(
                1,
                None,
                false,
                std::iter::empty(),
                std::iter::once(Box::new(test_layer) as ConsumerLayer),
            ),
            &[],
        )
        .expect("test tracing subscriber should be valid");

        let configs: S = dbt_jinja_utils::serde::from_yaml_raw(yaml, None, false, None)
            .expect("yaml deserializes into config type");

        // The data layer only records events emitted within an active span, so run
        // `init_project_config` inside a root span.
        let result = tracing::subscriber::with_default(subscriber, || {
            let _root = create_root_info_span(MockDynSpanEvent {
                name: "root".to_string(),
                flags: TelemetryOutputFlags::ALL,
                ..Default::default()
            })
            .entered();

            init_project_config::<T, S>(
                &Some(configs),
                Default::default(),
                None,
                disallow_plus_prefix,
                AdapterType::Snowflake,
            )

View on GitHub (pinned to 0267ce9170)

Solutions

1. Fix the YAML fixture so it matches the current schema of the target config struct
2. Check for recently renamed/removed config fields after upgrading and update fixtures accordingly
3. Convert the expect into an assertion with the deserialization error included so failures are readable
4. Validate the fixture against the struct's expected keys (+-prefixed keys under config) before running

Example fix

// before
let configs: S = from_yaml_raw(yaml, None, false, None).expect("yaml deserializes into config type");

// after
let configs: S = from_yaml_raw(yaml, None, false, None)
    .unwrap_or_else(|e| panic!("fixture yaml invalid: {e}"));

let configs: S = match from_yaml_raw(yaml, None, false, None) {
    Ok(c) => c,
    Err(e) => panic!("fixture yaml invalid: {e}"),
};

When it happens

Trigger: Adding or editing a test case whose YAML block contains a key or value shape that doesn't match the target config struct, so `from_yaml_raw::<S>` returns Err and the expect panics.

Common situations: Test authoring mistakes: typo'd keys, values of the wrong type, or config schema changes (renamed/removed fields) that make existing fixture YAML invalid.

Related errors

• Error message always present on ShouldBe::ButIsnt variant
• Error always present on ShouldBe::ButIsnt variant
• ProtoEnumSerde can only be derived for enums
• Should be able to serialize job labels
• test tracing subscriber should be valid

AI-assisted analysis of dbt-labs/dbt-core@0267ce9170 (2026-09-07). Data as JSON: /api/errors/def3e2489b0ec88f. Report an issue: GitHub.