tauri-apps/tauri · error

failed to read capabilities

Error message

failed to read capabilities

What it means

Build-time panic in tauri-codegen reading OUT_DIR/capabilities.json — the cache of the app's capability files written by tauri-build. std::fs::read_to_string(&capabilities_file_path).expect("failed to read capabilities") fires when the file exists (the exists() check passed) but the read fails: permission loss, deletion or locking between check and read, or non-UTF-8 bytes.

Source

Thrown at crates/tauri-codegen/src/context.rs:405

        key: #key.into(),
        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 so capabilities.json is regenerated
2. Serialize builds on the same target directory (CI locking, disable rust-analyzer during release builds)
3. Fix ownership/permissions of target/ and never mix root/user builds
4. Stop external tools (antivirus, indexers, backup) from touching target/

Example fix

# before: panic: failed to read capabilities

# after
cargo clean && cargo build

# remove torn capability caches from interrupted builds before compiling
find target -name capabilities.json -size -10c -delete 2>/dev/null || true

When it happens

Trigger: generate_context! reading capabilities.json while a parallel cargo build, antivirus, or cleanup process removes or locks it; target directory shared across users; truncated cache from a build that was killed mid-write.

Common situations: Concurrent CI jobs sharing one target volume; rust-analyzer racing a command-line build; one build step executed as root leaving root-owned artifacts.

Related errors

• Couldn't find capabilities directory at {}
• failed to read plugin manifest map
• failed to parse capabilities
• failed to resolve ACL
• unable to create autogenerated commands dir

AI-assisted analysis of tauri-apps/tauri@52e4b6e71d (2026-08-20). Data as JSON: /api/errors/15e53693131caf34. Report an issue: GitHub.