Visual Studio 2026 support

[isanych]

Describe the bug
VS 2026 insider is available now, I'm using cmake built with VS2026 support (master branch of https://gitlab.kitware.com/cmake/cmake - version 4.2 is not released yet) which is working properly with VS2026 in my testing, but even when I set VCPKG_VISUAL_STUDIO_PATH vcpkg using 14.44 compiler instead of 14.50 (C:\opt\vs2026\VC\Tools\MSVC\14.44.35207 instead of C:\opt\vs2026\VC\Tools\MSVC\14.50.35503 in my setup)

When I add

set(VCPKG_PLATFORM_TOOLSET v145)

to triplet file I'm getting next error

error: in triplet x64-windows: Unable to find a valid Visual Studio instance
  at "C:\opt\vs2026"
  with toolset version v145
The following Visual Studio instances were considered:
  C:\opt\vs2022
  C:\opt\vs2019
  C:\opt\vs2026
The following paths were examined for Visual Studio instances:
  C:\opt\vs2022\VC\Auxiliary/Build\vcvarsall.bat
  C:\opt\vs2019\VC\Auxiliary/Build\vcvarsall.bat
  C:\opt\vs2026\VC\Auxiliary/Build\vcvarsall.bat

Environment

• OS: Windows 11 25H2
• Compiler: cl 19.50.35503 from Visual Studio 2026 v18.0.0-insiders

To Reproduce
Steps to reproduce the behavior:

1. Build cmake with VS2026 support from master branch or get nightly build - https://cmake.org/files/dev/?C=M;O=D and put it in path
2. set VCPKG_VISUAL_STUDIO_PATH=C:\opt\vs2026 (otherwise VS2022 is used)
3. set VCPKG_FORCE_SYSTEM_BINARIES=1 (to use cmake with VS2026 support)
4. vcpkg install abseil:x64-windows
5. Observe old compiler used in buildtrees\detect_compiler\config-x64-windows-out.log

#COMPILER_C_VERSION#19.44.35215.0
#COMPILER_C_ID#MSVC
#COMPILER_C_PATH#C:/opt/vs2026/VC/Tools/MSVC/14.44.35207/bin/Hostx64/x64/cl.exe
#COMPILER_CXX_VERSION#19.44.35215.0
#COMPILER_CXX_ID#MSVC
#COMPILER_CXX_PATH#C:/opt/vs2026/VC/Tools/MSVC/14.44.35207/bin/Hostx64/x64/cl.exe

6. Add set(VCPKG_PLATFORM_TOOLSET v145) to triplets/x64-windows.cmake
7. get Unable to find a valid Visual Studio instance error

Expected behavior
When VS 2026 used, v145 toolset supported and used by default

Failure logs
C:\tmp\vcpkg\buildtrees\detect_compiler\stdout-x64-windows.log

-- Found external ninja('1.12.1').
-- Configuring x64-windows
[1/1] "C:/opt/apps/cmake/current/bin/cmake.exe" -E chdir ".." "C:/opt/apps/cmake/current/bin/cmake.exe" "C:/tmp/vcpkg/scripts/detect_compiler" "-G" "Ninja" "-DCMAKE_BUILD_TYPE=Release" "-DCMAKE_INSTALL_PREFIX=C:/tmp/vcpkg/packages/detect_compiler_x64-windows" "-DVCPKG_COMPILER_CACHE_FILE=C:/tmp/vcpkg/installed/vcpkg/compiler-file-hash-cache.json" "-DBUILD_SHARED_LIBS=ON" "-DVCPKG_CHAINLOAD_TOOLCHAIN_FILE=C:/tmp/vcpkg/scripts/toolchains/windows.cmake" "-DVCPKG_TARGET_TRIPLET=x64-windows" "-DVCPKG_SET_CHARSET_FLAG=ON" "-DVCPKG_PLATFORM_TOOLSET=v143" "-DCMAKE_EXPORT_NO_PACKAGE_REGISTRY=ON" "-DCMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY=ON" "-DCMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY=ON" "-DCMAKE_INSTALL_SYSTEM_RUNTIME_LIBS_SKIP=TRUE" "-DCMAKE_VERBOSE_MAKEFILE=ON" "-DVCPKG_APPLOCAL_DEPS=OFF" "-DCMAKE_TOOLCHAIN_FILE=C:/tmp/vcpkg/scripts/buildsystems/vcpkg.cmake" "-DCMAKE_ERROR_ON_ABSOLUTE_INSTALL_DESTINATION=ON" "-DVCPKG_CXX_FLAGS=" "-DVCPKG_CXX_FLAGS_RELEASE=" "-DVCPKG_CXX_FLAGS_DEBUG=" "-DVCPKG_C_FLAGS=" "-DVCPKG_C_FLAGS_RELEASE=" "-DVCPKG_C_FLAGS_DEBUG=" "-DVCPKG_CRT_LINKAGE=dynamic" "-DVCPKG_LINKER_FLAGS=" "-DVCPKG_LINKER_FLAGS_RELEASE=" "-DVCPKG_LINKER_FLAGS_DEBUG=" "-DVCPKG_TARGET_ARCHITECTURE=x64" "-DCMAKE_INSTALL_LIBDIR:STRING=lib" "-DCMAKE_INSTALL_BINDIR:STRING=bin" "-D_VCPKG_ROOT_DIR=C:/tmp/vcpkg" "-DZ_VCPKG_ROOT_DIR=C:/tmp/vcpkg" "-D_VCPKG_INSTALLED_DIR=C:/tmp/vcpkg/installed" "-DVCPKG_MANIFEST_INSTALL=OFF"
-- The C compiler identification is MSVC 19.44.35215.0
-- The CXX compiler identification is MSVC 19.44.35215.0
#COMPILER_HASH#37968c396ae4fe042c6ac7cb0118f08bcc5350f2
#COMPILER_C_HASH#3c62be3c178526242f2c45cf8ccbe3c55048a1a8
#COMPILER_C_VERSION#19.44.35215.0
#COMPILER_C_ID#MSVC
#COMPILER_C_PATH#C:/opt/vs2026/VC/Tools/MSVC/14.44.35207/bin/Hostx64/x64/cl.exe
#COMPILER_CXX_HASH#3c62be3c178526242f2c45cf8ccbe3c55048a1a8
#COMPILER_CXX_VERSION#19.44.35215.0
#COMPILER_CXX_ID#MSVC
#COMPILER_CXX_PATH#C:/opt/vs2026/VC/Tools/MSVC/14.44.35207/bin/Hostx64/x64/cl.exe
-- Configuring done (0.7s)
-- Generating done (0.0s)
CMake Warning:
  Manually-specified variables were not used by the project:

    BUILD_SHARED_LIBS
    CMAKE_INSTALL_BINDIR
    CMAKE_INSTALL_LIBDIR
    _VCPKG_ROOT_DIR


-- Build files have been written to: C:/tmp/vcpkg/buildtrees/detect_compiler/x64-windows-rel

[timercrack]

I'm also experiencing this issue. CMake works fine with the VS2026 toolchain and builds my projects successfully. However, vcpkg fails to detect the VS2026 instance:

PS D:\Github\vcpkg> vcpkg install cairo
Computing installation plan...
error: in triplet x64-windows: Unable to find a valid Visual Studio instance
Could not locate a complete Visual Studio instance
The following paths were examined for Visual Studio instances:
  d:\Program Files\Microsoft Visual Studio\2026\VC\Auxiliary/Build\vcvarsall.bat

Would be great to see official support for VS2026 detection in vcpkg soon.

[gvanem]

Igor Kostenko (@isanych)

get Unable to find a valid Visual Studio instance error

In vcpkg.exe, this is from a missing toolset in vcpkg-tool/src/vcpkg/vcpkgpath.cpp:
auto candidate = Util::find_if(vs_toolsets, ..) return nothing. Approx. line 1250.

In cmake.exe, the message "could not find any instance of Visual Studio.", is the same; a missing toolset in Source/cmGlobalVisualStudioGenerator.cxx:
if (!this->vsSetupAPIHelper.GetVSInstanceInfo(vsInstance)) {. Approx. line 618.

Both messages are for the same bloody reason; they fail in the COM-call to GetVSInstanceInfo() since the
component is not properly registered. Only some insiders at MS knows the proper fix for this mess.

Ref. cmake's Source/cmVSSetupHelper.cxx and this

[dsvensson]

Seems fixed? microsoft/vcpkg-tool#1787

I updated to latest and re-ran vcpkg/bootstrap-vcpkg.bat, after this the dependencies are built with the correct toolchain version again.

[isanych]

Seems fixed? microsoft/vcpkg-tool#1787

I updated to latest and re-ran vcpkg/bootstrap-vcpkg.bat, after this the dependencies are built with the correct toolchain version again.

I've tested this change even before it was merged, and something was not working for me - but I don't remember details already.
Now testing stable VS2026 with cmake 4.2 rc3 - and it looks like everything is working.
I'll do more testing and will close the issue if would not find anything too bad.

[dsvensson]

Also works with 4.1.2 as well, with the ninja generator at least.

[isanych]

working in my testing now

[jeremy-visionaid]

Has anybody else tried with VS Build Tools? In a container, I'm getting:

    Unable to determine appropriate generator for triplet x64-windows:

        ENV{VisualStudioVersion} : 18.0
        platform toolset: v145
        architecture    : x64

But it works OK on desktop with VS Pro 2026

[isanych]

Has anybody else tried with VS Build Tools? In a container, I'm getting:

    Unable to determine appropriate generator for triplet x64-windows:

        ENV{VisualStudioVersion} : 18.0
        platform toolset: v145
        architecture    : x64

But it works OK on desktop with VS Pro 2026

yep, I see the same, reopening issue and updating description

[isanych]

Actually I messed up testing in container, with latest vcpkg tool it is working, Jeremy Powell (@jeremy-visionaid) are you sure that you are using latest vcpkg.exe ?

[zhangqi2023]

CMake scripts should add support about visual studio 2026,
see code at scripts/cmake/vcpkg_configure_cmake.cmake:31

 if(DEFINED ENV{VisualStudioVersion})
        if("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL  "12.99" AND
           "$ENV{VisualStudioVersion}" VERSION_GREATER_EQUAL  "12.0" AND
           NOT "${VCPKG_TARGET_ARCHITECTURE}" STREQUAL "arm64")
            set(generator "Visual Studio 12 2013")
        elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL  "14.99" AND
               NOT "${VCPKG_TARGET_ARCHITECTURE}" STREQUAL "arm64")
            set(generator "Visual Studio 14 2015")
        elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL  "15.99")
            set(generator "Visual Studio 15 2017")
        elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL  "16.99")
            set(generator "Visual Studio 16 2019")
        elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL  "17.99")
            set(generator "Visual Studio 17 2022")
        endif()
    endif()

and code at scripts/buildsystems/vcpkg.cmake:269

elseif(CMAKE_GENERATOR STREQUAL "Visual Studio 16 2019")
        set(Z_VCPKG_TARGET_TRIPLET_ARCH x64)
    elseif(CMAKE_GENERATOR STREQUAL "Visual Studio 17 2022" AND CMAKE_VS_PLATFORM_NAME_DEFAULT STREQUAL "ARM64")
        set(Z_VCPKG_TARGET_TRIPLET_ARCH arm64)
    elseif(CMAKE_GENERATOR STREQUAL "Visual Studio 17 2022")
        set(Z_VCPKG_TARGET_TRIPLET_ARCH x64)
    elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin" AND DEFINED CMAKE_OSX_ARCHITECTURES)

[isanych]

CMake scripts should add support about visual studio 2026, see code at scripts/cmake/vcpkg_configure_cmake.cmake:31

张琪-igg-com (@zhangqi2023) cmake added vs2026 in 4.2 (not released yet, only rc3 is available), see https://gitlab.kitware.com/cmake/cmake/-/issues/27213

[zhangqi2023]

CMake scripts should add support about visual studio 2026, see code at scripts/cmake/vcpkg_configure_cmake.cmake:31

if(DEFINED ENV{VisualStudioVersion})
if("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL "12.99" AND
"$ENV{VisualStudioVersion}" VERSION_GREATER_EQUAL "12.0" AND
NOT "${VCPKG_TARGET_ARCHITECTURE}" STREQUAL "arm64")
set(generator "Visual Studio 12 2013")
elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL "14.99" AND
NOT "${VCPKG_TARGET_ARCHITECTURE}" STREQUAL "arm64")
set(generator "Visual Studio 14 2015")
elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL "15.99")
set(generator "Visual Studio 15 2017")
elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL "16.99")
set(generator "Visual Studio 16 2019")
elseif("$ENV{VisualStudioVersion}" VERSION_LESS_EQUAL "17.99")
set(generator "Visual Studio 17 2022")
endif()
endif()
and code at scripts/buildsystems/vcpkg.cmake:269

elseif(CMAKE_GENERATOR STREQUAL "Visual Studio 16 2019")
set(Z_VCPKG_TARGET_TRIPLET_ARCH x64)
elseif(CMAKE_GENERATOR STREQUAL "Visual Studio 17 2022" AND CMAKE_VS_PLATFORM_NAME_DEFAULT STREQUAL "ARM64")
set(Z_VCPKG_TARGET_TRIPLET_ARCH arm64)
elseif(CMAKE_GENERATOR STREQUAL "Visual Studio 17 2022")
set(Z_VCPKG_TARGET_TRIPLET_ARCH x64)
elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin" AND DEFINED CMAKE_OSX_ARCHITECTURES)

Igor Kostenko (@isanych) script vcpkg_configure_cmake.cmake and vcpkg.cmake all in vcpkg