tauri-apps/tauri · error

failed to parse capabilities

Error message

failed to parse capabilities

What it means

Build-time panic in tauri-codegen: serde_json::from_str over OUT_DIR/capabilities.json .expect("failed to parse capabilities") fails when the cached capabilities file is invalid JSON or no longer matches the structure the current tauri-codegen expects. The cache is produced by tauri-build from src-tauri/capabilities/*; a mismatch means a corrupt/truncated artifact or a version skew between writer and reader.

Source

Thrown at crates/tauri-codegen/src/context.rs:406

        crypto_keys: std::boxed::Box::new(::tauri::utils::pattern::isolation::Keys::new().expect("unable to generate cryptographically secure keys for Tauri \"Isolation\" Pattern")),
      })
    }
  };

  let acl_file_path = out_dir.join(ACL_MANIFESTS_FILE_NAME);
  let acl: BTreeMap<String, Manifest> = if acl_file_path.exists() {
    let acl_file =
      std::fs::read_to_string(acl_file_path).expect("failed to read plugin manifest map");
    serde_json::from_str(&acl_file).expect("failed to parse plugin manifest map")
  } else {
    Default::default()
  };

  let capabilities_file_path = out_dir.join(CAPABILITIES_FILE_NAME);
  let capabilities_from_files = if capabilities_file_path.exists() {
    let capabilities_json =
      std::fs::read_to_string(&capabilities_file_path).expect("failed to read capabilities");
    serde_json::from_str(&capabilities_json).expect("failed to parse capabilities")
  } else {
    Default::default()
  };
  let capabilities = get_capabilities(
    &config,
    capabilities_from_files,
    additional_capabilities.as_deref(),
  )
  .unwrap();

  let resolved = Resolved::resolve(&acl, capabilities, target).expect("failed to resolve ACL");

  let acl_tokens = map_lit(
    quote! { ::std::collections::BTreeMap },
    &acl,
    str_lit,
    identity,
  );

View on GitHub (pinned to 52e4b6e71d)

Solutions

1. cargo clean and rebuild
2. Align Tauri crate versions: `cargo tree -i tauri-utils` / `cargo tree -i tauri-build`, fix duplicates
3. Add/modify capability files only while no build is running, then rebuild
4. Clear CI build caches keyed on Cargo.lock after any Tauri dependency change

Example fix

# before: panic: failed to parse capabilities

# after
cargo clean && cargo build

# validate the capability cache parses before the codegen step runs
python3 -c "import json;json.load(open('target/debug/build'))" 2>/dev/null || cargo clean

When it happens

Trigger: Building after a Tauri upgrade with a stale capabilities.json in OUT_DIR; a build interrupted while writing the file; mixed tauri crate versions in one workspace producing schema drift.

Common situations: Tauri minor upgrade without cleaning target; CI cache reuse of target across version bumps; editing capabilities while a build runs, leaving a torn cache.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to parse plugin manifest map
• failed to read capabilities
• failed to resolve ACL
• Couldn't find capabilities directory at {}
• You did not select any capabilities to update

AI-assisted analysis of tauri-apps/tauri@52e4b6e71d (2026-08-20). Data as JSON: /api/errors/5ce03dc451ad07d7. Report an issue: GitHub.