thakis: ptal? you are the only clang person I know :)

All bots use update.py, and it's working fine. Something on your machine is configured weirdly.

update.py is supposed to download a prebuilt binary; the cmake bits should only run on certain bots.

Were there any error messages further up?

Does starting over anew help?

I have started over anew in two different computers... It checks out the code from SVN, and then when it comes to compiling the code just checked out, that happens.

I'm doing update.py --bootstrap --force-local-build --extra-tools

Why are you doing this? If you don't pass any of these flags, it'll work. Since you are passing this, you're probably trying to do something more than just building chrome. What's your goal?

I want to build empty_string, and possibly change it a bit. I have been following the instructions provided in https://chromium.googlesource.com/chromium/src/+/lkcr/docs/clang_tool_refactoring.md

Thanks, that's good to know :-) I think dcheng had this building on Windows at some point, and the clang packaging bots also run this code path, so it's possible to get it to work somehow, we just need to figure out what's different on your system.

Here's the output of a recent working run: https://logs.chromium.org/v/?s=chromium%2Fbb%2Ftryserver.chromium.win%2Fwin_upload_clang%2F286%2F%2B%2Frecipes%2Fsteps%2Fpackage_clang%2F0%2Fstdout

Can you compare if that looks similar to what you're seeing locally? Are there any differences?

I can spot a few differences right away:

The bot is using C:\\b\\rr\\tmp_8mrxd\\w\\src\\third_party\\depot_tools\\win_toolchain\\vs_files\\1180cb75833ea365097e279efb2d5d7a42dee4b0\\win_sdk\\Bin\\SetEnv.Cmd

The computers I've tried are using: C:\\Program Files (x86)\\Microsoft Visual Studio\\2017\\Community\\VC\\Auxiliary\\Build\\vcvarsall.bat

The bot is target x64 while the computer I'm using is targeting amd64 (not sure if that's a problem)

SetEnv works ok in the bot, and it prints:
-- The C compiler identification is MSVC 19.11.25507.1
-- The CXX compiler identification is MSVC 19.11.25507.1
-- The ASM compiler identification is MSVC


On my computer, vcvarsall.bat print:
**********************************************************************
** Visual Studio 2017 Developer Command Prompt v15.5.6
** Copyright (c) 2017 Microsoft Corporation
**********************************************************************
[vcvarsall.bat] Environment initialized for: 'x64'
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
-- The ASM compiler identification is unknown

I think that's that I can spot from the output.

I think x64 and amd64 morally mean the same thing.

If you add something like

    if msvc_arch == 'x64':
      msvc_arch = 'amd64'

here https://cs.chromium.org/chromium/src/tools/clang/scripts/update.py?q=update.py&sq=package:chromium&dr=C&l=206 , does that change anything?

just bear with me some minutes... checking the code out.

That doesn't work because amd64 is not supported by MSVSVersion.py

  File "C:\google\src\tools\gyp\pylib\gyp\MSVSVersion.py", line 82, in _SetupScriptInternal
    assert target_arch in ('x86', 'x64'), "target_arch not supported"
AssertionError: target_arch not supported

Shouldn't vcvarsall.bat be called with x64, since amd64 is not supported?

Hm, looking at https://cs.chromium.org/chromium/src/tools/gyp/pylib/gyp/MSVSVersion.py?dr=C&q=SetupScript&sq=package:chromium&l=93 I suppose it's supposed to do the right thing if you're in a 64-bit msvc shell. That env var is set over here:

C:\src\llvm-build-goma10>set | findstr PROCESSOR_ARCH
PROCESSOR_ARCHITECTURE=AMD64


I think if you want this config to work, I'm afraid you'll have to debug it a bit yourself :-/

I'm not sure if you noticed, but it tries to use the compiler that's about to be built as the toolset for the bootstrap. Here's what the log says:

Compiling the C compiler identification source file "CMakeCCompilerId.c" failed.
Compiler: Y:/dev/chromium/src/third_party/llvm-bootstrap-install/bin/clang-cl.exe 

This is the path set as LLVM_BOOTSTRAP_INSTALL_DIR, to be used as the install path for this run. I'm not sure what is leading CMake to try to run the compiler at that path.