When meson is attempting to locate MSVC using vswhere.exe, it has the opportunity to select the appropriate toolset for the target architecture. vsdevcmd.bat gives the following options in VS2019:

Syntax: vsdevcmd.bat [options]
[options] :
    -arch=architecture : Architecture for compiled binaries/libraries
           ** x86 [default]
           ** amd64
           ** arm
           ** arm64
    -host_arch=architecture : Architecture of compiler binaries
           ** x86 [default]
           ** amd64

vsdevcmd.bat was introduced in VS2017 under Common7/Tools and replaces VC/Auxiliary/Build/vcvarsall.bat. I have been told that vcvarsall.bat is gone in VS2022 (not verified).

At present, the target architecture is hard-coded to either amd64 or ARM, making it impossible, for example, to build a Windows x86 executable:

The current workaround is of course to run vsdevcmd -arch=x86 before running meson setup, but this is troublesome when integrating with other shells (for example as noted in #2622 (comment)).

We encountered this issue when trying to simplify our meson builds at keymanapp/keyman#8279; I would submit a patch for meson but really not sure the right way to address this within meson 😄. Our desired approach would be for meson to figure out which toolchain architecture is needed for the target and use that to call vsdevcmd.bat/vcvarsall.bat with the -arch parameter.

The host architecture may be important for very large projects -- given it is either x86 or amd64, this should be easy enough to ascertain with the existing native architecture check?