[REGRESSION] Ninja generator no longer being used after update

[EthanRutherford]

Brief Issue Summary

Cmake Tools no longer detects Ninja generator after update.

CMake Tools Diagnostics

{
  "os": "win32",
  "vscodeVersion": "1.116.0",
  "cmtVersion": "1.23.51",
  "configurations": [
    {
      "folder": "NO",
      "cmakeVersion": "4.2.3",
      "configured": true,
      "generator": "Visual Studio 18 2026",
      "usesPresets": false,
      "compilers": {}
    }
  ],
  "cpptoolsIntegration": {
    "isReady": false,
    "hasCodeModel": false,
    "activeBuildType": "",
    "buildTypesSeen": [],
    "requests": [],
    "responses": [],
    "partialMatches": [],
    "targetCount": 0,
    "executablesCount": 0,
    "librariesCount": 0,
    "targets": []
  },
  "settings": [
    {
      "communicationMode": "automatic",
      "useCMakePresets": "auto",
      "configureOnOpen": true
    }
  ]
}

Debug Log

[cmake] -- Selecting Windows SDK version 10.0.26100.0 to target Windows 10.0.26200.
[cmake] CMake Error: Error: generator : Visual Studio 18 2026
[cmake] Does not match the generator used previously: Ninja
[cmake] Either remove the CMakeCache.txt file and CMakeFiles directory or choose a different binary directory.
[cmake] 
[cmake] -- Configuring incomplete, errors occurred!

Additional Information

My build tools should not change their own configuration after an update.

[EthanRutherford]

Just to be extremely clear here, automatic usage and preference of ninja over vs generators is a documented feature of cmake tools.

[EthanRutherford]

Small suggestion, perhaps we shouldn't be vibe-coding changes to an extension with 57 million unique installs.

[yanghhhhhhh]

Hi @EthanRutherford , thank you for reporting this issue. We tried to check this issue on Visual Studio Code v1.116.0 + CMake Tools v1.23.51. But we can't reproduce this issue. Could you help to take a look at it? If we missed something, please let us know. In order for us to investigate this further, could you please provide a sample project to us that can reproduce this issue? Thanks.

[EthanRutherford]

Your gif shows the repro.

1. Have visual studio 2026 installed
2. Have Ninja installed and available on PATH
3. Fresh install the extension and select the visual studio kit
4. Run a cmake configure on a cmake project
5. Observe that the generator used is msbuild, and not Ninja

The documentation for this extension states that it will prefer Ninja over visual studio as the generator if it detects it on the PATH. I linked to the relevant doc in a comment above.

I'm versions before 1.23.51, this automatic detection and preference for Ninja as the generator worked by default, and after updating to 1.23.51 it has begun trying to use visual studio as the generator instead.