Fix: Wait for the subprocess that opens the browser window, preventing zombie processes

Fixes #1488

CHANGELOG.md

@@ -17,6 +17,7 @@ Status of the `main` branch. Changes prior to the next official version change w
     This allows the dashboard to display the configuration while the project provided at startup is still initialising. #1064
   - Fix empty executions queue displaying "Loading..."
   - Tray manager: Add NixOS-support for AppIndicator-based trays (e.g., most Wayland-trays) to the package in flake.nix.
+  - Fix: Wait for the subprocess that opens the browser window, preventing zombie processes #1488 
 
 # v1.5.3 (2026-05-26)
 

src/serena/dashboard.py

@@ -813,13 +813,14 @@ def open_url_in_browser(url: str, use_subprocess: bool = False) -> None:
     if use_subprocess:
         # Use a subprocess to avoid any output from webbrowser.open being written to stdout
         try:
-            subprocess.Popen(
+            p = subprocess.Popen(
                 [sys.executable, "-c", f"import webbrowser; webbrowser.open({url!r})"],
                 stdin=subprocess.DEVNULL,
                 stdout=subprocess.DEVNULL,
                 stderr=subprocess.DEVNULL,
                 start_new_session=False,
             )
+            threading.Thread(target=p.wait, daemon=True).start()
         except Exception as e:
             # Subprocess creation can fail in rare cases (e.g. on some Linux systems; possibly subprocess/glibc bug)
             # See #1363