Could not find local Visual Studio install on x86_64-pc-windows-msv if C++ x64/x86 Build Tools (Latest) is not installed

[Archengius]

cc-rs seems to be unable to locate local VS install and build tools unless Latest build tools component is installed from the Visual Studio Installer. Any other MSVC build tool packages (out of supported or pinned version build tool packages that can be installed from Individual Components tab) will result in cc-rs being unable to find and use Visual Studio install.

Steps to reproduce:

1. Open Visual Studio Installer
2. Install Visual Studio Community 2022
3. Select "Desktop Development with C++" workload
4. Unselect "MSVC v143 - VS 2022 C++ x64/x86 build tools (Latest)" component
5. Go to individual components tab and select other version of MSVC build tools here ("MSVC v143 - VS 2022 C++ x64/x86 build tools (v14.38 - v17.8)" in my case).
6. Install the selected components
7. Try compiling a native crate ("`libsqlite3-sys v0.27.0" in my case).
8. Observe that cc-rs cannot find installation path for cl.exe

[NobodyXu]

We support lookup of vs15, for older version we simply look it up in env var PATH

cc-rs/src/windows/find_tools.rs

Line 453 in 48f676e

if is_vscmd_target(target, env_getter) == Some(false) {

[ChrisDenton]

There is code that attempts to find the non-default msvc build tools:

cc-rs/src/windows/find_tools.rs

Lines 795 to 822 in 48f676e

	// Try to open the default version file.
	let mut version_path: PathBuf =
	dir.join(r"VC\Auxiliary\Build\Microsoft.VCToolsVersion.default.txt");
	let mut version_file = if let Ok(f) = File::open(&version_path) {
	f
	} else {
	// If the default doesn't exist, search for other version files.
	// These are in the form Microsoft.VCToolsVersion.v143.default.txt
	// where `143` is any three decimal digit version number.
	// This sorts versions by lexical order and selects the highest version.
	let mut version_file = String::new();
	version_path.pop();
	for file in version_path.read_dir().ok()? {
	let name = file.ok()?.file_name();
	let name = name.to_str()?;
	if name.starts_with("Microsoft.VCToolsVersion.v")
	&& name.ends_with(".default.txt")
	&& name > &version_file
	{
	version_file.replace_range(.., name);
	}
	}
	if version_file.is_empty() {
	return None;
	}
	version_path.push(version_file);
	File::open(version_path).ok()?
	};

However, it's quite possible it's too fragile and some update to Visual Studio broke it. A workaround is to use the "Developer Command Prompt" or "Developer Powershell" because then the environment will be set appropriately (e.g. cl.exe will be in PATH).

[ChrisDenton]

Possibly a more robust way to do this is to fallback to iterating %VCINSTALLDIR%\Tools\MSVC and picking whichever directory has the highest version number.