Build from source on Windows - Cargo error without Rust toolchain

Follows on from https://github.com/nodejs/node/issues/63213

Version

v27.0.0-pre 0e8fb913d857b0d4123995e401293a0c9ee5efd8

Platform

Microsoft Windows NT 10.0.26200.0 x64

Subsystem

build

What steps will reproduce the bug?

On Windows 11 25H2, follow prerequisite Manual install instructions using:

• Python 3.14.5
• Visual Basic 2026 Build Tools 18.6.0 (May 2026)
  • C++ Clang Compiler for Windows (Microsoft.VisualStudio.Component.VC.Llvm.Clang)
  • MSBuild support for LLVM (clang-cl) toolset (Microsoft.VisualStudio.Component.VC.Llvm.ClangToolset)
• NASM 3.01
• Do not install a Rust toolchain (and otherwise ensure that there is no rustc or cargo installed).

In PowerShell 7 terminal, execute:

git clone https://github.com/nodejs/node
cd node
git switch main
git clean -xfd # if repeating
.\vcbuild.bat
Release\node -e "console.log('Hello from Node.js', process.version)"

How often does it reproduce? Is there a required condition?

Always if there is no Rust toolchain installed. Test with the following, which should both return errors:

rustc --version
cargo --version

What is the expected behavior? Why is that the expected behavior?

If a Rust toolchain is not installed, vcbuild.bat should warn (check for rustc & cargo) that Temporal support is disabled and continue to build without error.

This is implied by the documentation section Building Node.js with Temporal support and the fact that on Linux, builds succeed if there is no Rust toolchain installed.

If --v8-enable-temporal-support and --v8-disable-temporal-support are both omitted, configure.py probes for cargo and rustc. If either is missing, a warning is printed and Temporal support is disabled.

It should also be possible to disable temporal support actively when building under Windows.

What do you see instead?

Build emits error message and continues:

C:\Program Files (x86)\Microsoft Visual Studio\18\BuildTools\MSBuild\Microsoft\VC\v180\Microsoft.CppCommon.targets(254,5): error MSB8066: Custom build for 'Cargo.toml' exited with code 1
. [C:\Users\mikem\github\NODEJS\node\deps\crates\node_crates.vcxproj]

Directory Release is not created. (out\Release also contains no node.exe)

Additional information

Logs

.\vcbuild.bat
Looking for Python
Python found in C:\Users\mikem\AppData\Local\Microsoft\WindowsApps\\python.exe
Python 3.14.5
Looking for NASM
ClangCL is required because the Node.js version being compiled is >= 24.
Looking for Visual Studio 2026
calling: "C:\Program Files (x86)\Microsoft Visual Studio\18\BuildTools\VC\\Auxiliary\Build\vcvarsall.bat" amd64
**********************************************************************
** Visual Studio 2026 Developer Command Prompt v18.6.0
** Copyright (c) 2026 Microsoft Corporation
**********************************************************************
[vcvarsall.bat] Environment initialized for: 'x64'
Found MSVS version 18.0
Found Clang version 20.1.8
configure  --dest-cpu=x64 --clang-cl=20.1.8
[WARNING] A shebang '/bin/sh' was found but does not match any supported template (e.g. '/usr/bin/python'), so it will be treated as an arbitrary command.
[WARNING] To prevent execution of programs that are not Python runtimes, set 'shebang_can_run_anything' to 'false' in your configuration file.
Node.js configure: Found Python 3.14.5...
Warning: Missing input files:
C:\Users\mikem\github\NODEJS\node\deps\uv\src\win\atomicops-inl.h
C:\Users\mikem\github\NODEJS\node\deps\inspector_protocol\crdtp\maybe.h
C:\Users\mikem\github\NODEJS\node\tools\v8_gypfiles\..\..\deps\v8\third_party\abseil-cpp\absl\base\internal\nullability_impl.h
C:\Users\mikem\github\NODEJS\node\tools\v8_gypfiles\..\..\deps\v8\third_party\abseil-cpp\absl\base\internal\fast_type_id.h
C:\Users\mikem\github\NODEJS\node\tools\v8_gypfiles\..\..\deps\v8\third_party\abseil-cpp\absl\base\internal\identity.h
INFO: configure completed successfully
Project files generated.

src\hdr_histogram.c(149,23): warning : incompatible pointer types passing 'uint32_t *' (aka 'unsigned int *') to parameter of type 'unsigned long *' [-Wincompatible-pointer-types] [C:\Us
ers\mikem\github\NODEJS\node\deps\histogram\histogram.vcxproj]
C:\Program Files (x86)\Microsoft Visual Studio\18\BuildTools\VC\Tools\Llvm\x64\lib\clang\20\include\intrin0.h(71,48): message : passing argument to parameter '_Index' here [C:\Users\mike
m\github\NODEJS\node\deps\histogram\histogram.vcxproj]
  In file included from src\hdr_histogram.c:18:
src\hdr_atomic.h(23,13): warning : unused function 'hdr_atomic_store_pointer' [-Wunused-function] [C:\Users\mikem\github\NODEJS\node\deps\histogram\histogram.vcxproj]
  histogram.vcxproj -> ..\..\out\Release\lib\histogram.lib
  cargo_build
  Traceback (most recent call last):
    File "C:\Users\mikem\github\NODEJS\node\deps\crates\cargo_build.py", line 60, in <module>
      main()
      ~~~~^^
    File "C:\Users\mikem\github\NODEJS\node\deps\crates\cargo_build.py", line 47, in main
      ret = subprocess.call(cmd)
    File "C:\Users\mikem\AppData\Local\Python\pythoncore-3.14-64\Lib\subprocess.py", line 396, in call
      with Popen(*popenargs, **kwargs) as p:
           ~~~~~^^^^^^^^^^^^^^^^^^^^^^
    File "C:\Users\mikem\AppData\Local\Python\pythoncore-3.14-64\Lib\subprocess.py", line 1039, in __init__
      self._execute_child(args, executable, preexec_fn, close_fds,
      ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                          pass_fds, cwd, env,
                          ^^^^^^^^^^^^^^^^^^^
      ...<5 lines>...
                          gid, gids, uid, umask,
                          ^^^^^^^^^^^^^^^^^^^^^^
                          start_new_session, process_group)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "C:\Users\mikem\AppData\Local\Python\pythoncore-3.14-64\Lib\subprocess.py", line 1553, in _execute_child
      hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
                         ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
                               # no special security
                               ^^^^^^^^^^^^^^^^^^^^^
      ...<4 lines>...
                               cwd,
                               ^^^^
                               startupinfo)
                               ^^^^^^^^^^^^
  FileNotFoundError: [WinError 2] The system cannot find the file specified
C:\Program Files (x86)\Microsoft Visual Studio\18\BuildTools\MSBuild\Microsoft\VC\v180\Microsoft.CppCommon.targets(254,5): error MSB8066: Custom build for 'Cargo.toml' exited with code 1
. [C:\Users\mikem\github\NODEJS\node\deps\crates\node_crates.vcxproj]

Start with deps/crates/cargo_build.py and the Windows build path invoked by vcbuild.bat; compare configure.py's cargo/rustc probe with the BUILDING.md Temporal support guidance and the reported Linux behavior. Reproduce with rustc and cargo unavailable, then verify that the Windows build completes without the Cargo project failure and that the documented way to disable Temporal support works.