CMakePresets.json - how to pass CMAKE_TOOLCHAIN_FILE ?

First: CMakePreset.json is a great improvement!

Please let me know how to provide toolchain file in CMakePresets.json

  "version": 1,
  "cmakeMinimumRequired": {
    "major": 3,
    "minor": 19,
    "patch": 0
  "configurePresets": [
      "name": "default",
      "displayName": "Default Config",
      "description": "Default build using Ninja generator",
      "generator": "Ninja",
      "binaryDir": "${sourceDir}/../../build/",
      "cacheVariables": {
        "CMAKE_TOOLCHAIN_FILE": "/path/to/GccToolchain.cmake"
# just preset option will not work:
cmake --preset=default

# I need to provide Toolcahin path anyway in commandline:
cmake --preset=default -DCMAKE_TOOLCHAIN_FILE='/path/to/GccToolchain.cmake'

Including CMAKE_TOOLCHAIN_FILE in the presets file should theoretically work. Please open an issue to report this.

it worked!
"CMAKE_TOOLCHAIN_FILE": { "type": "PATH", "value": "${sourceDir}/../../../../cmake/GccToolchain.cmake" },
I guess I had to mess up the file path on the first try.