tauri-apps/tauri · error

failed to parse icon {}: {}

Error message

failed to parse icon {}: {}

What it means

Compile-time panic in tauri-codegen's icon handling (tauri::image module used by generate_context!). new_ico reads the .ico file into memory and hands it to ico::IconDir::read; if the bytes are not a parseable ICO container (bad header/magic, truncated file), it panics with the icon path and the parse error.

Source

Thrown at crates/tauri-codegen/src/image.rs:55

    }
  }

  /// Cache the icon without any manipulation.
  pub fn new_raw(root: &TokenStream, icon: &Path) -> EmbeddedAssetsResult<Self> {
    let buf = Self::open(icon);
    Cached::try_from(buf).map(|cache| Self {
      cache,
      root: root.clone(),
      format: IconFormat::Raw,
    })
  }

  /// Cache an ICO icon as RGBA data, see [`ImageFormat::Image`].
  pub fn new_ico(root: &TokenStream, icon: &Path) -> EmbeddedAssetsResult<Self> {
    let buf = Self::open(icon);

    let icon_dir = ico::IconDir::read(Cursor::new(&buf))
      .unwrap_or_else(|e| panic!("failed to parse icon {}: {}", icon.display(), e));

    let entry = &icon_dir.entries()[0];
    let rgba = entry
      .decode()
      .unwrap_or_else(|e| panic!("failed to decode icon {}: {}", icon.display(), e))
      .rgba_data()
      .to_vec();

    Cached::try_from(rgba).map(|cache| Self {
      cache,
      root: root.clone(),
      format: IconFormat::Image {
        width: entry.width(),
        height: entry.height(),
      },
    })
  }

View on GitHub (pinned to 52e4b6e71d)

Solutions

1. Regenerate the full icon set from a single square PNG source: `npx tauri icon path/to/icon.png`
2. Verify the real format: `file icons/icon.ico` should report 'MS Windows icon resource'
3. Replace the corrupt file with a valid ICO produced by a proper converter (ImageMagick/GIMP)

Example fix

# before
file src-tauri/icons/icon.ico   # 'PNG image data' -> panic: failed to parse icon

# after
npx tauri icon ./app-icon.png   # regenerates valid icons incl. icon.ico
file src-tauri/icons/icon.ico   # 'MS Windows icon resource'

#!/usr/bin/env bash
for ico in src-tauri/icons/*.ico; do
  file "$ico" | grep -q 'MS Windows icon' || { echo "not a valid ICO: $ico"; exit 1; }
done

When it happens

Trigger: A file listed in bundle > icon that has an .ico extension but is not actually an ICO: a renamed PNG/JPEG, an HTML error page saved as icon.ico, a git-LFS pointer file, or a truncated download.

Common situations: Downloading icons from the web and trusting the extension; LFS not pulled on CI; manual conversion that produced an empty/corrupt file.

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

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• The isolation application path is set to `{dir:?}` but it do
• The isolation application does not contain a file setting th

AI-assisted analysis of tauri-apps/tauri@52e4b6e71d (2026-08-20). Data as JSON: /api/errors/1b5b0cea1841297a. Report an issue: GitHub.