# CMake presets: \`inherit\` makes it hard to include toolchain file
**URL:** https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784
**Category:** Code
**Created:** [March 28, 2023, 6:43am UTC](https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784 "2023-03-28T06:43:53Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@flodin](https://discourse.cmake.org/u/flodin)
#### Post date: [March 28, 2023, 6:43am UTC](https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784/1 "2023-03-28T06:43:53Z")
Hi,
We have a CMake structure where there is a common platform which can be built by itself or included via different sub-components.
Since the platform is always used by the sub-components we thought it a good fit to specify a CMakePresets.json file in the platform and the sub-components would simply include it.
```auto
|- common/
| |- platform/
| | |- CMakeLists.txt
| | |- CMakePresets.json
|- sub-component1/
| |- CMakeLists.txt
| |- CMakePresets.json (includes the platforms CMakePreset.json)
|- sub-component2/
| | - CMakeLists.txt
| | - CMakePresets.json (includes the platforms CMakePreset.json)
```
The `configurePresets` in the platforms CMakePresets.json looks something like this:
```auto
"configurePresets": [
{
"name": "linux",
"description": "Configure options specific for Linux",
"generator": "Ninja",
"toolchainFile": "${fileDir}/cmake/toolchains/linux.cmake"
},
{
"name": "linux-multi",
"inherits": "linux",
"description": "Multi-config linux setup",
"generator": "Ninja Multi-Config"
},
{
"name": "windows",
"description": "Configure options specific for Windows",
"generator": "Visual Studio 17 2022",
"architecture": {
"value": "x64"
},
"toolchainFile": "${fileDir}/cmake/toolchains/windows.cmake"
}
```
This worked fine when the sub-components simply included the platforms `CMakePresets.json` from their own. However, when users started to specify their own presets and used `inherit` on the platforms presets the `toolchainFile` didn’t work any longer since the `${fileDir}` macro is no evaluated in the context of the platform, but the sub-components: “All macros are evaluated in the context of the preset being used, even if the macro is in a field that was inherited from another preset.” [https://cmake.org/cmake/help/latest/manual/cmake-presets.7.html#macro-expansion](https://cmake.org/cmake/help/latest/manual/cmake-presets.7.html#macro-expansion)
Using the `CMAKE_TOOLCHAIN_FILE` is not an ideal solution for us (since it would require changing both the platform and all sub-components) since the sub-components typically include the platform after they’ve specified `project()` causing the toolchain file not to be included.
Given that we want to be able to build the platform by itself and via the sub-components, is it possible to use `inherit` in combination with the above `toolchainFile` inclusion?
---
### Author:  [@flodin](https://discourse.cmake.org/u/flodin)
#### Post date: [March 28, 2023, 12:23pm UTC](https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784/2 "2023-03-28T12:23:54Z")
To clarify, adding the following CMakeUserPresets.json to `sub-component1`:
```cmake
{
"version": 6,
"configurePresets": [{
"name": "default",
"inherits": "linux-multi", // defined in platform
"cacheVariables": {
...
}
}]
}
```
results in the following error:
```auto
cmake --preset default .
Preset CMake variables:
...
CMAKE_TOOLCHAIN_FILE:FILEPATH="/path/to/subcomponent1/cmake/toolchains/linux.cmake"
Using ccache /usr/bin/ccache
CMake Error at /usr/share/cmake-3.25/Modules/CMakeDetermineSystem.cmake:130 (message):
Could not find toolchain file:
/path/to/subcomponent1/cmake/toolchains/linux.cmake
Call Stack (most recent call first):
CMakeLists.txt:42 (project)
CMake Error: CMake was unable to find a build program corresponding to "Ninja Multi-Config". CMAKE_MAKE_PROGRAM is not set. You probably need to select a different build tool.
-- Configuring incomplete, errors occurred!
```
---
### Author:  [@bjornskov](https://discourse.cmake.org/u/bjornskov)
#### Post date: [February 15, 2024, 10:40am UTC](https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784/3 "2024-02-15T10:40:41Z")
Hi!
I am facing the same issue. Did you find a workaround for this?
For me it seems like a bug, as the fileDir should be the directory containing the preset, which should be this specific file. Otherwise there should be yet another macro defining this.
---
### Author:  [@flodin](https://discourse.cmake.org/u/flodin)
#### Post date: [February 16, 2024, 6:33am UTC](https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784/4 "2024-02-16T06:33:43Z")
Unfortunately not. We ended up moving everything from the toolchain files into the CMakePreset.json of the platform component.
Please let me know if you find a solution 🙂
---
### Author:  [@thetic](https://discourse.cmake.org/u/thetic)
#### Post date: [June 21, 2025, 12:10am UTC](https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784/5 "2025-06-21T00:10:49Z")
Has anyone found a workaround for this? It seems to prevent implementing any useful includes.
---
### Author:  [@Chardrazle](https://discourse.cmake.org/u/Chardrazle)
#### Post date: [August 8, 2025, 11:16am UTC](https://discourse.cmake.org/t/cmake-presets-inherit-makes-it-hard-to-include-toolchain-file/7784/6 "2025-08-08T11:16:02Z")
We just ran into this issue. We “solved” it by using an environment variable _that is under control of the presets_.
For example, in the “BasePresets.json”:
```auto
{
"version": 8,
"configurePresets": [
{
"name": "default",
"hidden": true,
"binaryDir": "$env{BASE_ROOT}/.build/${sourceDirName}",
"toolchainFile": "$env{BASE_ROOT}/where_we_keep_common_stuff/toolchain.cmake",
"environment": {
"BASE_ROOT": "${fileDir}"
}
}
]
}
```
Then in the project-specific presets we specify “where” the root is from _this_ file by overriding the env-var.
So if it is located one subdirectory away:
```auto
{
"version": 8,
"include": ["../BasePresets.json"],
"configurePresets": [
{
"name": "default-inherited",
"inherits": ["default"],
"hidden": true,
"environment": {
"BASE_ROOT": "${fileDir}/.."
}
},
{
"name": "an-actual-preset-for-the-project",
"inherits": ["default-inherited"]
}
]
}
```