Build error: QT dependency fails to build on Windows 10 when using VS BuildTools ("Could not find vcvarsall.bat")

[aps9]

Description

The QT dependencies fail to compile on Windows 10, when using Build Tools in place of a full Visual Studio 2022 installation.

Commit-id

88fb0c6

Build target

3. Windows build
   • https://github.com/google/mozc/blob/master/docs/build_mozc_in_windows.md

CI build status

1. passing

Environment

• OS: Windows 10
• Python version (optional): 3.9.13
• Qt5 version (optional): unknown, apparently I am following instructions to build QT 5 from source.
• Compiler version (optional): Visual Studio Build Tools 2020 (this is important) -- no full edition of VS 2020 is installed.

Build commands

Steps of command lines to reproduce your error.
(Starting in folder C:\Development )

1. python -m pip install six requests
2. (I updated pip as python requested, but I don't believe this is relevant).
3. git clone https://github.com/google/mozc.git
4. cd mozc\src
5. python build_tools/update_deps.py
6. "C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvarsamd64_x86.bat"
   (Note, this is different from the line specified in the instructions for regular VC builds. It is tailored to the limited installation of BuildTools.)
7. python build_tools/build_qt.py --release --confirm_license
   This is where it gets in trouble.

Error logs

extracting util/xkbdatagen/xkbdatagen.pro                                                                                                                                                                                                       Traceback (most recent call last):
  File "C:\Development\mozc\src\build_tools\build_qt.py", line 541, in <module>
    main()
  File "C:\Development\mozc\src\build_tools\build_qt.py", line 537, in main
    build_on_windows(args)
  File "C:\Development\mozc\src\build_tools\build_qt.py", line 437, in build_on_windows
    env = get_vs_env_vars('amd64_x86', args.vcvarsall_path)
  File "C:\Development\mozc\src\build_tools\build_qt.py", line 396, in get_vs_env_vars
    vcvarsall = get_vcvarsall(vcvarsall_path_hint)
  File "C:\Development\mozc\src\build_tools\build_qt.py", line 354, in get_vcvarsall
    raise FileNotFoundError('Could not find vcvarsall.bat')
FileNotFoundError: Could not find vcvarsall.bat

Additional context

Yes, I examined the file build_qt.py near line 354. The function get_vcvarsall searches for vcvarsall.bat in standard editions of Visual Studio, but it does not seem to have any provision for a Visual Studio BuildTools installation.

Part of the code looks like this:

  for edition in ['Community', 'Professional', 'Enterprise']:
    vcvarsall = pathlib.Path('C:\\', 'Program Files', 'Microsoft Visual Studio',
                             '2022', edition, 'VC', 'Auxiliary', 'Build',
                             'vcvarsall.bat')
    if vcvarsall.exists():
      return vcvarsall

  raise FileNotFoundError('Could not find vcvarsall.bat')

In my local copy, I added this before the raise statement, and it seemed to compile correctly after that:

  # Also check for BuildTools, which is a smaller installation.
  program_files_x86 = 'Program Files (x86)'
  edition = 'BuildTools'
  vcvarsall = pathlib.Path('C:\\', program_files_x86, 'Microsoft Visual Studio',
                           '2022', edition, 'VC', 'Auxiliary', 'Build',
                           'vcvarsall.bat')
  if vcvarsall.exists():
    return vcvarsall

The fresh VS 2020 BuildTools installation put itself in "Program Files (x86)" instead of Program Files. I don't know whether this is normal, or whether it's because I have some older installations of VS (2017 and 2019). However, in any case, the python code is not looking for a BuildTools installation.

Build instructions for Windows say that Build Tools for Visual Studio 2022 should work in place of the full installation of VS 2022:
"Build Tools for Visual Studio 2022 should also work"

This may be a small issue, but I appreciate your consideration.

[yukawa]

Thank you for the report.

Coincidentally we recently submitted c777896 for our internal build servers where Build Tools for Visual Studio 2022 are installed in C:\VS\VC. With that I guess it's already possible for you to work around your case without changing the source code as follow.

python build_qt.py --release --confirm_license --vcvarsall_path="C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvarsall.bat"

I'll also update build_qt.py so that it can also search vcvarsall.bat under Program Files (x86) as it shouldn't be a big deal anyway.

[aps9]

I tried the command-line option you suggested, and it seems to work in getting past this issue.

If you are updating build_qt.py, then you might also consider adding 'BuildTools' to the list of editions.

Thank you for the update.