bug: dart.EXE.exe double extension on Windows

[dukguru]

Bug Description

When running flet build windows -v on Windows, the build fails with a "command not found" error because the Dart executable path has .exe extension added twice, resulting in dart.EXE.exe.

Environment

• OS: Windows 11 (Version 10.0.26200.7628)
• Flet version: 0.80.4
• Flet-CLI version: 0.80.4
• Flutter version: 3.38.8 (Channel stable)
• Python version: 3.10+

Root Cause

In flet_cli/commands/flutter_base.py, the find_flutter_batch() method uses shutil.which() to find the Dart executable on Windows. This function returns the full path with .EXE extension (uppercase).

Steps to Reproduce

1. Install Flet on Windows 11
2. Run flet build windows -v
3. Observe the error during native assets compilation

Proposed Fix

In flet_cli/commands/flutter_base.py, modify the find_flutter_batch() method to strip the .exe extension on Windows:

def find_flutter_batch(self, exe_filename: str):
    assert self.required_flutter_version
    install_dir = get_flutter_dir(str(self.required_flutter_version))
    ext = ".bat" if is_windows() else ""
    batch_path = os.path.join(install_dir, "bin", f"{exe_filename}{ext}")
    if os.path.exists(batch_path):
        return batch_path

    batch_path = shutil.which(exe_filename)
    if not batch_path:
        return None
    if is_windows() and batch_path.endswith(".file"):
        return batch_path.replace(".file", ".bat")
    # Remove .exe/.EXE extension on Windows if present (Flutter adds it back)
    if is_windows() and batch_path.lower().endswith(".exe"):
        return batch_path[:-4]
    return batch_path

[FeodorFitsner]

I'm wondering how do you get flutter.exe in there?

Flutter 3.38.8 zip for Windows contains .bat only:

How did you install 3.38.8? Do you use fvm? What do you have in your Flutter's bin folder?

[dukguru]

I installed the flutter sdk by installing the flutter plugin in vscode.

The problem occurred when calling "dart.exe" instead of "flutter.exe"

And flutter build tries to use flutter/bin/cache/dart-sdk/bin/dart.exe

[ndonkoHenri]

I remember seeing this issue on ci when using subosito flutter action: https://github.com/flet-dev/flet-build-test/actions/runs/21333031233/job/61400671377

[FeodorFitsner]

Alright, now I see it - it's in cache. It makes sense now: