{"record":{"id":"deac2982ca447103","repo":"wasmerio/wasmer","slug":"app-field-empty","errorCode":null,"errorMessage":"app field empty","messagePattern":"app field empty","errorType":"exception","errorClass":"DeployError","httpStatus":null,"severity":"error","filePath":"lib/sdk/src/app/deploy.rs","lineNumber":144,"sourceCode":"    .await?;\n\n    progress(DeployProgress::Waiting(opts.wait));\n    wait_app(client, &version, opts.wait, opts.make_default).await\n}\n\nasync fn wait_app(\n    client: &WasmerClient,\n    version: &DeployAppVersion,\n    wait: WaitMode,\n    make_default: bool,\n) -> Result<(DeployApp, DeployAppVersion), DeployError> {\n    const PROBE_TIMEOUT: Duration = Duration::from_secs(60 * 5);\n    use wasmer_config::app::HEADER_APP_VERSION_ID;\n\n    let app_id = version\n        .app\n        .as_ref()\n        .ok_or_else(|| DeployError::Api(anyhow::anyhow!(\"app field empty\")))?\n        .id\n        .inner()\n        .to_string();\n\n    let app = wasmer_backend_api::query::get_app_by_id(client, app_id.clone())\n        .await\n        .map_err(DeployError::Api)?;\n\n    match wait {\n        WaitMode::Deployed => {}\n        WaitMode::Reachable => {\n            tokio::time::sleep(Duration::from_secs(2)).await;\n            let check_url = if make_default { &app.url } else { &version.url };\n            let http = reqwest::Client::builder()\n                .connect_timeout(Duration::from_secs(10))\n                .timeout(Duration::from_secs(90))\n                .redirect(reqwest::redirect::Policy::none())\n                .build()","sourceCodeStart":126,"sourceCodeEnd":162,"githubUrl":"https://github.com/wasmerio/wasmer/blob/8c4b9ee9d33fb2068863fbb3d328683e7e6ff7f5/lib/sdk/src/app/deploy.rs#L126-L162","documentation":"wait_app in lib/sdk/src/app/deploy.rs extracts the app id from the AppVersion response returned by the deploy API. The GraphQL AppVersion type's `app` field is nullable; if the backend returns a version without an associated app, the code raises DeployError::Api(\"app field empty\") instead of panicking. It indicates an unexpected/incomplete server response during deploy polling.","triggerScenarios":"deploy_app calls wait_app with an AppVersion whose `app` field is null — e.g. the version was deleted concurrently, the backend returned a partial object, or the API returned an inconsistent response for a freshly created version.","commonSituations":"Deploy against a backend/registry with a schema mismatch (older server omitting the app field); the app was deleted between version creation and the wait; auth scope issues causing the server to omit related entities; transient backend bugs.","solutions":["Retry the deploy — if transient backend inconsistency, a fresh deploy_app run usually succeeds.","Verify you are authenticated against the correct registry/backend (`wasmer whoami`) and your token has access to the app.","Check the app still exists on the backend (wasmer app list / web dashboard) before redeploying.","Update the CLI/SDK — older clients may mis-handle newer API responses.","If persistent, inspect the raw GraphQL response (enable debug logging) and report the backend issue."],"exampleFix":"// before: assumes app is always present\nwait_app(client, &version, domain).await?;\n// after: fail fast with context if the API response is incomplete\nanyhow::ensure!(version.app.is_some(), \"API returned AppVersion {:?} without an app; cannot wait for deployment\", version.id);\nwait_app(client, &version, domain).await?;","handlingStrategy":"try-catch","validationCode":"// guard before waiting on a version\nfn version_has_app(v: &AppVersion) -> bool { v.app.is_some() }\nanyhow::ensure!(version_has_app(&version), \"AppVersion {:?} has no app field; aborting wait\", version.id);","typeGuard":"fn has_app(v: &AppVersion) -> Option<&App> { v.app.as_ref() }","tryCatchPattern":"match deploy_app(...).await {\n    Err(DeployError::Api(e)) if e.to_string().contains(\"app field empty\") => {\n        eprintln!(\"Backend returned an incomplete AppVersion; check the app exists and retry the deploy\");\n        std::process::exit(1);\n    }\n    Ok(v) => v,\n    Err(e) => return Err(e.into()),\n}","preventionTips":["Confirm the app exists on the backend before deploying a new version","Use a current CLI/SDK version matching the backend API schema","Check token permissions cover reading the app entity","Add retry-with-backoff around deploy for transient backend inconsistencies"],"tags":["rust","api","deploy","graphql","null-field"],"backgroundTag":"unexpected-api-response","analyzedSha":"8c4b9ee9d33fb2068863fbb3d328683e7e6ff7f5","analyzedAt":"2026-09-01T23:06:31.009Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-09T06:17:21.866Z"}