From c3254ca00ccc1ba7c92a98adcbfd1e5f11ec545a Mon Sep 17 00:00:00 2001
From: Carl
 <3e3d196dd9859e7da50eb419bfc7e219beb702c8730adc23dfec69f30d5064df@buzz.block.builderlab.xyz>
Date: Mon, 21 Sep 2026 15:46:28 -0700
Subject: [PATCH 1/2] Label macOS worktree Dock icons through the shared
 launcher

Signed-off-by: Carl <3e3d196dd9859e7da50eb419bfc7e219beb702c8730adc23dfec69f30d5064df@buzz.block.builderlab.xyz>
---
 docs/contributing.md                     |  18 ++
 scripts/desktop-dev.mjs                  |  22 ++-
 scripts/generate-dev-icon.swift          | 216 +++++++++++++++++++++++
 scripts/worktree-icon.mjs                |  70 ++++++++
 tests/integration/dev-commands.test.mjs  |   4 +
 tests/integration/worktree-icon.test.mjs | 185 +++++++++++++++++++
 6 files changed, 506 insertions(+), 9 deletions(-)
 create mode 100644 scripts/generate-dev-icon.swift
 create mode 100644 scripts/worktree-icon.mjs
 create mode 100644 tests/integration/worktree-icon.test.mjs

diff --git a/docs/contributing.md b/docs/contributing.md
index 9ede80cdd..17f1b3da8 100644
--- a/docs/contributing.md
+++ b/docs/contributing.md
@@ -106,6 +106,24 @@ do not copy private keys, `node_modules`, build output, `.npmrc`, or other ignor
 files. Install hooks separately as described below so existing custom hooks are
 never silently replaced.
 
+### Worktree Dock labels (macOS)
+
+`just desktop` adds the current branch suffix to the Dock icon in linked Git
+worktrees (for example, `person/my-feature` shows `my-feature`). Detached
+worktrees use the checkout directory name. Restart the desktop command after
+switching or renaming a branch; no Cargo clean is needed.
+
+The launcher reuses the existing badge design and generates an icon under the
+ignored `src-tauri/target/dev-icons/` directory. The generated bytes determine its
+filename, so changed labels, source artwork, or rendering update Tauri's embedded
+icon even with a warm build. Generation requires macOS Swift/AppKit and `iconutil`;
+if it fails, startup warns and continues with the ordinary icon. Explicit Tauri
+`--config` arguments still take precedence over the generated icon and port.
+
+Ordinary checkouts, non-macOS launches, and `pnpm tauri build` keep their existing
+icons. This does not change the app identifier, credentials, profiles, ports, or
+notification settings.
+
 ## Interactive product iteration
 
 While shaping the first version, default to **edit → human tries the running app
diff --git a/scripts/desktop-dev.mjs b/scripts/desktop-dev.mjs
index c0131ad3d..e541ff66e 100644
--- a/scripts/desktop-dev.mjs
+++ b/scripts/desktop-dev.mjs
@@ -1,4 +1,6 @@
 import { spawnSync } from "node:child_process";
+import { fileURLToPath } from "node:url";
+import { worktreeIcon } from "./worktree-icon.mjs";
 
 const args = process.argv.slice(2);
 const forwarded = [];
@@ -23,18 +25,20 @@ for (; index < args.length && args[index] !== "--"; index++) {
   }
 }
 
+const config = {};
+const icon = worktreeIcon(fileURLToPath(new URL("../", import.meta.url)));
+if (icon) config.bundle = { icon: [icon] };
 if (port !== undefined) {
   // Tauri's own --port controls its static-file server, not our Vite server.
+  config.build = {
+    devUrl: `http://localhost:${port}`,
+    beforeDevCommand: `pnpm dev:desktop --port ${port}`,
+  };
+}
+if (Object.keys(config).length) {
   // Prepend: Tauri treats everything after a bare positional as runner args.
-  forwarded.unshift(
-    "--config",
-    JSON.stringify({
-      build: {
-        devUrl: `http://localhost:${port}`,
-        beforeDevCommand: `pnpm dev:desktop --port ${port}`,
-      },
-    }),
-  );
+  // Explicit user configs merge afterward and retain precedence.
+  forwarded.unshift("--config", JSON.stringify(config));
 }
 // Runner/application arguments after -- belong to Tauri, including any --port.
 forwarded.push(...args.slice(index));
diff --git a/scripts/generate-dev-icon.swift b/scripts/generate-dev-icon.swift
new file mode 100644
index 000000000..b324478cc
--- /dev/null
+++ b/scripts/generate-dev-icon.swift
@@ -0,0 +1,216 @@
+#!/usr/bin/env swift
+
+import AppKit
+import Foundation
+
+// Ported from block/buzz scripts/generate-dev-icon.swift.
+// Generate a dev icon with worktree name badge
+// Usage: generate-dev-icon.swift <input-icns> <output-icns> <label>
+
+guard CommandLine.arguments.count == 4 else {
+    fputs("Usage: \(CommandLine.arguments[0]) <input-icns> <output-icns> <label>\n", stderr)
+    exit(1)
+}
+
+let inputPath = CommandLine.arguments[1]
+let outputPath = CommandLine.arguments[2]
+let label = CommandLine.arguments[3]
+
+func sanitizedPathComponent(_ value: String) -> String {
+    let lowered = value.lowercased()
+    let sanitizedScalars = lowered.unicodeScalars.map { scalar -> Character in
+        switch scalar {
+        case "a"..."z", "0"..."9":
+            return Character(scalar)
+        default:
+            return "-"
+        }
+    }
+    let collapsed = String(sanitizedScalars).replacingOccurrences(
+        of: "-+",
+        with: "-",
+        options: .regularExpression
+    )
+    let trimmed = collapsed.trimmingCharacters(in: CharacterSet(charactersIn: "-"))
+    return trimmed.isEmpty ? "dev" : trimmed
+}
+
+guard let iconImage = NSImage(contentsOfFile: inputPath) else {
+    fputs("Failed to load image: \(inputPath)\n", stderr)
+    exit(1)
+}
+
+// Get the largest representation for best quality
+guard let rep = iconImage.representations.max(by: { $0.pixelsWide < $1.pixelsWide }) else {
+    fputs("No image representations found\n", stderr)
+    exit(1)
+}
+
+let size = NSSize(width: rep.pixelsWide, height: rep.pixelsHigh)
+
+let newImage = NSImage(size: size)
+newImage.lockFocus()
+
+// Draw the original icon
+iconImage.draw(in: NSRect(origin: .zero, size: size))
+
+// Configure badge
+let singleLineHeight = size.height * 0.22
+let padding = size.width * 0.03
+let maxBadgeWidth = size.width * 0.9
+
+// Text attributes - calculate font size to fit
+let maxFontSize = singleLineHeight * 0.65
+var fontSize = maxFontSize
+var attributes: [NSAttributedString.Key: Any]
+
+// Helper to wrap text on `-` characters
+func wrapText(_ text: String, maxWidth: CGFloat, attributes: [NSAttributedString.Key: Any]) -> [String] {
+    let singleLineSize = (text as NSString).size(withAttributes: attributes)
+    if singleLineSize.width <= maxWidth {
+        return [text]
+    }
+
+    // Split on `-` and try to form lines
+    let parts = text.components(separatedBy: "-")
+    if parts.count == 1 {
+        return [text]  // No `-` to wrap on
+    }
+
+    var lines: [String] = []
+    var currentLine = ""
+
+    for (index, part) in parts.enumerated() {
+        let separator = index == 0 ? "" : "-"
+        let testLine = currentLine.isEmpty ? part : currentLine + separator + part
+        let testSize = (testLine as NSString).size(withAttributes: attributes)
+
+        if testSize.width <= maxWidth || currentLine.isEmpty {
+            currentLine = testLine
+        } else {
+            lines.append(currentLine)
+            currentLine = part
+        }
+    }
+    if !currentLine.isEmpty {
+        lines.append(currentLine)
+    }
+
+    return lines
+}
+
+// Find font size that fits (allowing up to 2 lines)
+var lines: [String] = []
+repeat {
+    attributes = [
+        .font: NSFont.systemFont(ofSize: fontSize, weight: .bold),
+        .foregroundColor: NSColor.white
+    ]
+    lines = wrapText(label, maxWidth: maxBadgeWidth - padding * 4, attributes: attributes)
+    fontSize -= 1
+} while (lines.count > 2 || lines.contains {
+    ($0 as NSString).size(withAttributes: attributes).width > maxBadgeWidth - padding * 4
+}) && fontSize > 1
+
+// Calculate text dimensions using typographic metrics
+let lineHeight = (lines.first! as NSString).size(withAttributes: attributes).height
+let textHeight = lineHeight * CGFloat(lines.count)
+let maxLineWidth = lines.map { ($0 as NSString).size(withAttributes: attributes).width }.max() ?? 0
+
+// Badge dimensions based on text
+let badgeHeight = textHeight + padding * 2
+let cornerRadius = badgeHeight * 0.2
+let badgeWidth = maxLineWidth + padding * 4
+let badgeX = (size.width - badgeWidth) / 2
+let badgeY = size.height - badgeHeight - padding - size.height * 0.05
+
+// Draw badge background (light blue semi-transparent)
+let badgePath = NSBezierPath(roundedRect: NSRect(x: badgeX, y: badgeY, width: badgeWidth, height: badgeHeight),
+                              xRadius: cornerRadius, yRadius: cornerRadius)
+NSColor(calibratedRed: 0.4, green: 0.7, blue: 1.0, alpha: 0.85).setFill()
+badgePath.fill()
+
+// Draw text centered in badge (multiple lines, bottom to top)
+for (index, line) in lines.reversed().enumerated() {
+    let lineSize = (line as NSString).size(withAttributes: attributes)
+    let textX = badgeX + (badgeWidth - lineSize.width) / 2
+    let textY = badgeY + padding + lineHeight * CGFloat(index)
+    (line as NSString).draw(at: NSPoint(x: textX, y: textY), withAttributes: attributes)
+}
+
+newImage.unlockFocus()
+
+// First, create PNG data at multiple sizes for icns
+guard let tiffData = newImage.tiffRepresentation,
+      let bitmapRep = NSBitmapImageRep(data: tiffData) else {
+    fputs("Failed to create bitmap representation\n", stderr)
+    exit(1)
+}
+
+// For simplicity, we'll create a PNG and then use iconutil if available,
+// or just save as PNG for the icon (Tauri can use PNG)
+guard let pngData = bitmapRep.representation(using: .png, properties: [:]) else {
+    fputs("Failed to create PNG data\n", stderr)
+    exit(1)
+}
+
+// If output is .icns, we need to create an iconset and use iconutil
+if outputPath.hasSuffix(".icns") {
+    let tempDir = FileManager.default.temporaryDirectory
+    let iconsetParent = tempDir.appendingPathComponent(
+        "staged-dev-\(sanitizedPathComponent(label))-\(UUID().uuidString)",
+        isDirectory: true
+    )
+    let iconsetPath = iconsetParent.appendingPathComponent("icon.iconset", isDirectory: true)
+    try! FileManager.default.createDirectory(at: iconsetPath, withIntermediateDirectories: true)
+
+    // Generate all required sizes for iconset
+    let sizes: [(name: String, size: Int)] = [
+        ("icon_16x16", 16),
+        ("icon_16x16@2x", 32),
+        ("icon_32x32", 32),
+        ("icon_32x32@2x", 64),
+        ("icon_128x128", 128),
+        ("icon_128x128@2x", 256),
+        ("icon_256x256", 256),
+        ("icon_256x256@2x", 512),
+        ("icon_512x512", 512),
+        ("icon_512x512@2x", 1024)
+    ]
+
+    for (name, targetSize) in sizes {
+        let resizedImage = NSImage(size: NSSize(width: targetSize, height: targetSize))
+        resizedImage.lockFocus()
+        NSGraphicsContext.current?.imageInterpolation = .high
+        newImage.draw(in: NSRect(x: 0, y: 0, width: targetSize, height: targetSize))
+        resizedImage.unlockFocus()
+
+        guard let resizedTiff = resizedImage.tiffRepresentation,
+              let resizedBitmap = NSBitmapImageRep(data: resizedTiff),
+              let resizedPng = resizedBitmap.representation(using: .png, properties: [:]) else {
+            continue
+        }
+
+        let filePath = iconsetPath.appendingPathComponent("\(name).png")
+        try! resizedPng.write(to: filePath)
+    }
+
+    // Use iconutil to create icns
+    let process = Process()
+    process.executableURL = URL(fileURLWithPath: "/usr/bin/iconutil")
+    process.arguments = ["-c", "icns", iconsetPath.path, "-o", outputPath]
+    try! process.run()
+    process.waitUntilExit()
+
+    try? FileManager.default.removeItem(at: iconsetParent)
+
+    if process.terminationStatus != 0 {
+        fputs("iconutil failed\n", stderr)
+        exit(1)
+    }
+} else {
+    // Just save as PNG
+    try! pngData.write(to: URL(fileURLWithPath: outputPath))
+}
+
+print("Generated: \(outputPath)")
diff --git a/scripts/worktree-icon.mjs b/scripts/worktree-icon.mjs
new file mode 100644
index 000000000..bb0b52259
--- /dev/null
+++ b/scripts/worktree-icon.mjs
@@ -0,0 +1,70 @@
+import { execFileSync, spawnSync } from "node:child_process";
+import { createHash } from "node:crypto";
+import {
+  mkdirSync,
+  mkdtempSync,
+  readFileSync,
+  renameSync,
+  rmSync,
+} from "node:fs";
+import { basename, join } from "node:path";
+
+// Keep optional macOS artwork out of the shared launcher's argument handling.
+export function worktreeIcon(cwd, platform = process.platform) {
+  if (platform !== "darwin") return null;
+  const git = (...args) =>
+    execFileSync("git", args, {
+      cwd,
+      encoding: "utf8",
+      stdio: ["ignore", "pipe", "pipe"],
+    }).trim();
+  let label;
+  try {
+    if (
+      git("rev-parse", "--path-format=absolute", "--git-dir") ===
+      git("rev-parse", "--path-format=absolute", "--git-common-dir")
+    )
+      return null;
+    const branch = git("branch", "--show-current");
+    label = branch
+      ? branch.split("/").at(-1)
+      : basename(git("rev-parse", "--show-toplevel"));
+  } catch {
+    return null;
+  }
+
+  let temporary;
+  try {
+    const directory = join(cwd, "src-tauri/target/dev-icons");
+    mkdirSync(directory, { recursive: true });
+    temporary = mkdtempSync(join(directory, "staging-"));
+    const output = join(temporary, "icon.icns");
+    const result = spawnSync(
+      "swift",
+      [
+        join(cwd, "scripts/generate-dev-icon.swift"),
+        join(cwd, "src-tauri/icons/icon.icns"),
+        output,
+        label,
+      ],
+      { cwd, stdio: "inherit" },
+    );
+    if (result.error || result.status !== 0)
+      throw result.error ?? new Error("Icon generator failed");
+    // Tauri caches the embedded bytes, not the source icon's modification time.
+    // A content-keyed path changes TAURI_CONFIG and invalidates warm Cargo builds.
+    const digest = createHash("sha256")
+      .update(readFileSync(output))
+      .digest("hex");
+    const icon = join(directory, `${digest}.icns`);
+    renameSync(output, icon);
+    return icon;
+  } catch {
+    console.warn(
+      "Worktree icon could not be generated; using the ordinary Buzz icon.",
+    );
+    return null;
+  } finally {
+    if (temporary) rmSync(temporary, { recursive: true, force: true });
+  }
+}
diff --git a/tests/integration/dev-commands.test.mjs b/tests/integration/dev-commands.test.mjs
index 4613f667f..0eeb746fa 100644
--- a/tests/integration/dev-commands.test.mjs
+++ b/tests/integration/dev-commands.test.mjs
@@ -27,6 +27,10 @@ function recipe(name, ...args) {
       new URL("../../scripts/desktop-dev.mjs", import.meta.url),
       path.join(directory, "scripts/desktop-dev.mjs"),
     );
+    copyFileSync(
+      new URL("../../scripts/worktree-icon.mjs", import.meta.url),
+      path.join(directory, "scripts/worktree-icon.mjs"),
+    );
     // Run the real recipes and adapter, recording only the package-manager boundary.
     symlinkSync(process.execPath, path.join(directory, "node"));
     writeFileSync(
diff --git a/tests/integration/worktree-icon.test.mjs b/tests/integration/worktree-icon.test.mjs
new file mode 100644
index 000000000..f03f1c007
--- /dev/null
+++ b/tests/integration/worktree-icon.test.mjs
@@ -0,0 +1,185 @@
+import assert from "node:assert/strict";
+import { execFileSync, spawnSync } from "node:child_process";
+import {
+  copyFileSync,
+  mkdtempSync,
+  mkdirSync,
+  readFileSync,
+  readdirSync,
+  rmSync,
+  writeFileSync,
+} from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import test from "node:test";
+
+// Real Git worktrees and subprocesses; only Swift rendering and pnpm are stubs.
+// The macOS-only launcher wiring also runs on a Mac, without opening an app.
+function fixture(t) {
+  const directory = mkdtempSync(path.join(tmpdir(), "buzz-worktree-icon-"));
+  t.after(() => rmSync(directory, { recursive: true, force: true }));
+  const env = { ...process.env };
+  // Git hooks export repository selectors; never let fixtures touch the real repo.
+  for (const key of [
+    "GIT_DIR",
+    "GIT_COMMON_DIR",
+    "GIT_WORK_TREE",
+    "GIT_IMPLICIT_WORK_TREE",
+    "GIT_INDEX_FILE",
+    "GIT_OBJECT_DIRECTORY",
+    "GIT_ALTERNATE_OBJECT_DIRECTORIES",
+    "GIT_PREFIX",
+  ])
+    delete env[key];
+  const git = (...args) =>
+    execFileSync("git", args, { env, stdio: "pipe" }).toString().trim();
+  const main = path.join(directory, "main");
+  const linked = path.join(directory, 'linked "checkout"');
+  const emptyHooks = path.join(directory, "hooks");
+  mkdirSync(emptyHooks);
+  git("init", "--initial-branch=main", main);
+  git("-C", main, "config", "core.hooksPath", emptyHooks);
+  git(
+    "-C",
+    main,
+    "-c",
+    "user.name=Test",
+    "-c",
+    "user.email=test@example.com",
+    "-c",
+    "commit.gpgsign=false",
+    "commit",
+    "--allow-empty",
+    "-m",
+    "fixture",
+  );
+  git("-C", main, "worktree", "add", "-b", "person/first-label", linked);
+  const tools = path.join(directory, "tools");
+  mkdirSync(tools);
+  const render = (body) =>
+    writeFileSync(
+      path.join(tools, "swift"),
+      `#!${process.execPath}\n${body}\n`,
+      { mode: 0o755 },
+    );
+  render('require("node:fs").writeFileSync(process.argv[4], process.argv[5]);');
+  writeFileSync(
+    path.join(tools, "pnpm"),
+    `#!${process.execPath}\nconsole.log(JSON.stringify(process.argv.slice(2)));`,
+    { mode: 0o755 },
+  );
+  env.PATH = `${tools}${path.delimiter}${env.PATH}`;
+  for (const cwd of [main, linked]) {
+    mkdirSync(path.join(cwd, "scripts"));
+    for (const file of ["desktop-dev.mjs", "worktree-icon.mjs"]) {
+      copyFileSync(
+        new URL(`../../scripts/${file}`, import.meta.url),
+        path.join(cwd, "scripts", file),
+      );
+    }
+  }
+  const run = (cwd, args) => {
+    const result = spawnSync(process.execPath, args, {
+      cwd,
+      env,
+      encoding: "utf8",
+      timeout: 10_000,
+    });
+    assert.ifError(result.error);
+    assert.equal(result.status, 0, result.stderr);
+    return result;
+  };
+  const icon = (cwd, platform = "darwin") => {
+    const result = run(cwd, [
+      "--input-type=module",
+      "-e",
+      `import { worktreeIcon } from './scripts/worktree-icon.mjs'; console.log(JSON.stringify(worktreeIcon(process.cwd(), ${JSON.stringify(platform)})));`,
+    ]);
+    return { ...result, icon: JSON.parse(result.stdout.trim()) };
+  };
+  return { main, linked, git, render, icon, run };
+}
+
+test("only linked macOS worktrees receive a content-keyed, current-branch icon", (t) => {
+  const { main, linked, git, icon } = fixture(t);
+  assert.equal(icon(main).icon, null);
+  for (const platform of ["linux", "win32"])
+    assert.equal(icon(linked, platform).icon, null);
+  const first = icon(linked).icon;
+  assert.equal(readFileSync(first, "utf8"), "first-label");
+  assert.equal(
+    icon(linked).icon,
+    first,
+    "unchanged bytes keep a stable configuration",
+  );
+  const head = git("-C", linked, "rev-parse", "HEAD");
+  git("-C", linked, "branch", "-m", "person/second-label");
+  assert.equal(git("-C", linked, "rev-parse", "HEAD"), head);
+  const second = icon(linked).icon;
+  assert.notEqual(
+    second,
+    first,
+    "new bytes must change Tauri config for warm Cargo builds",
+  );
+  assert.equal(readFileSync(second, "utf8"), "second-label");
+  assert.equal(
+    readFileSync(first, "utf8"),
+    "first-label",
+    "in-flight builds retain their original bytes",
+  );
+  git("-C", linked, "checkout", "--detach");
+  assert.equal(readFileSync(icon(linked).icon, "utf8"), path.basename(linked));
+  assert.ok(
+    readdirSync(path.dirname(first)).every((name) => name.endsWith(".icns")),
+    "staging files are cleaned up",
+  );
+});
+
+test("failed generation warns, removes partial output, and falls back", (t) => {
+  const { linked, render, icon } = fixture(t);
+  render(
+    'require("node:fs").writeFileSync(process.argv[4], "partial"); process.exit(1);',
+  );
+  const result = icon(linked);
+  assert.equal(result.icon, null);
+  assert.match(result.stderr, /using the ordinary Buzz icon/);
+  assert.deepEqual(
+    readdirSync(path.join(linked, "src-tauri/target/dev-icons")),
+    [],
+  );
+});
+
+test("macOS launcher combines icon and port before explicit config and runner arguments", {
+  skip: process.platform !== "darwin",
+}, (t) => {
+  const { linked, run, render } = fixture(t);
+  const forwarded = [
+    "--config",
+    '{"bundle":{"icon":["custom.icns"]}}',
+    "--runner",
+    "echo",
+    "two words",
+    "--",
+    "--port",
+    "app-port",
+    "$(pnpm injected)",
+  ];
+  const launch = () =>
+    JSON.parse(
+      run(linked, ["scripts/desktop-dev.mjs", "--port=1431", ...forwarded])
+        .stdout,
+    );
+  const call = launch();
+  assert.deepEqual(call.slice(0, 3), ["tauri", "dev", "--config"]);
+  const config = JSON.parse(call[3]);
+  assert.equal(readFileSync(config.bundle.icon[0], "utf8"), "first-label");
+  assert.deepEqual(config.build, {
+    devUrl: "http://localhost:1431",
+    beforeDevCommand: "pnpm dev:desktop --port 1431",
+  });
+  assert.deepEqual(call.slice(4), forwarded);
+  render("process.exit(1);");
+  const fallback = launch();
+  assert.deepEqual(JSON.parse(fallback[3]), { build: config.build });
+  assert.deepEqual(fallback.slice(4), forwarded);
+});

From 871e6691edeb3c44ea0a4ad50379be506bcdd577 Mon Sep 17 00:00:00 2001
From: Carl
 <3e3d196dd9859e7da50eb419bfc7e219beb702c8730adc23dfec69f30d5064df@buzz.block.builderlab.xyz>
Date: Mon, 21 Sep 2026 16:21:59 -0700
Subject: [PATCH 2/2] Keep Dock display labels out of temporary paths

Signed-off-by: Carl <3e3d196dd9859e7da50eb419bfc7e219beb702c8730adc23dfec69f30d5064df@buzz.block.builderlab.xyz>
---
 scripts/generate-dev-icon.swift          | 21 +---------------
 tests/integration/worktree-icon.test.mjs | 32 ++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/scripts/generate-dev-icon.swift b/scripts/generate-dev-icon.swift
index b324478cc..76bbebe0f 100644
--- a/scripts/generate-dev-icon.swift
+++ b/scripts/generate-dev-icon.swift
@@ -16,25 +16,6 @@ let inputPath = CommandLine.arguments[1]
 let outputPath = CommandLine.arguments[2]
 let label = CommandLine.arguments[3]
 
-func sanitizedPathComponent(_ value: String) -> String {
-    let lowered = value.lowercased()
-    let sanitizedScalars = lowered.unicodeScalars.map { scalar -> Character in
-        switch scalar {
-        case "a"..."z", "0"..."9":
-            return Character(scalar)
-        default:
-            return "-"
-        }
-    }
-    let collapsed = String(sanitizedScalars).replacingOccurrences(
-        of: "-+",
-        with: "-",
-        options: .regularExpression
-    )
-    let trimmed = collapsed.trimmingCharacters(in: CharacterSet(charactersIn: "-"))
-    return trimmed.isEmpty ? "dev" : trimmed
-}
-
 guard let iconImage = NSImage(contentsOfFile: inputPath) else {
     fputs("Failed to load image: \(inputPath)\n", stderr)
     exit(1)
@@ -158,7 +139,7 @@ guard let pngData = bitmapRep.representation(using: .png, properties: [:]) else
 if outputPath.hasSuffix(".icns") {
     let tempDir = FileManager.default.temporaryDirectory
     let iconsetParent = tempDir.appendingPathComponent(
-        "staged-dev-\(sanitizedPathComponent(label))-\(UUID().uuidString)",
+        "staged-dev-\(UUID().uuidString)",
         isDirectory: true
     )
     let iconsetPath = iconsetParent.appendingPathComponent("icon.iconset", isDirectory: true)
diff --git a/tests/integration/worktree-icon.test.mjs b/tests/integration/worktree-icon.test.mjs
index f03f1c007..5c090957e 100644
--- a/tests/integration/worktree-icon.test.mjs
+++ b/tests/integration/worktree-icon.test.mjs
@@ -12,6 +12,7 @@ import {
 import { tmpdir } from "node:os";
 import path from "node:path";
 import test from "node:test";
+import { fileURLToPath } from "node:url";
 
 // Real Git worktrees and subprocesses; only Swift rendering and pnpm are stubs.
 // The macOS-only launcher wiring also runs on a Mac, without opening an app.
@@ -183,3 +184,34 @@ test("macOS launcher combines icon and port before explicit config and runner ar
   assert.deepEqual(JSON.parse(fallback[3]), { build: config.build });
   assert.deepEqual(fallback.slice(4), forwarded);
 });
+
+test("real macOS renderer accepts long display labels", {
+  skip: process.platform !== "darwin",
+}, (t) => {
+  const directory = mkdtempSync(path.join(tmpdir(), "buzz-icon-render-"));
+  t.after(() => rmSync(directory, { recursive: true, force: true }));
+  const root = fileURLToPath(new URL("../../", import.meta.url));
+  const output = path.join(directory, "icon.icns");
+  // Valid Git suffix, but too long when combined with a prefix and UUID as a path.
+  const label = "a".repeat(220);
+  const result = spawnSync(
+    "swift",
+    [
+      path.join(root, "scripts/generate-dev-icon.swift"),
+      path.join(root, "src-tauri/icons/icon.icns"),
+      output,
+      label,
+    ],
+    { encoding: "utf8", timeout: 60_000 },
+  );
+  assert.ifError(result.error);
+  assert.equal(result.status, 0, result.stderr);
+  // Decode the generated artifact rather than asserting artwork or internal names.
+  execFileSync("/usr/bin/iconutil", [
+    "-c",
+    "iconset",
+    output,
+    "-o",
+    path.join(directory, "decoded.iconset"),
+  ]);
+});