[bug] Inconsistent build_type with user_presets_path

[AlexandrePTJ]

Describe the bug

When setting user_presets_path as in example, resulting ConanPresets.json file is inconsistent.
When build_type=Debug, it creates presets with release and vice versa in addition to include expected CMakePreset.

Then it cannot build as presets are invalid.

How to reproduce it

Follow instructions from https://docs.conan.io/2/examples/tools/cmake/cmake_toolchain/extend_own_cmake_presets.html

From a fresh debian docker (docker run --rm -it debian) :

# Install minimal tools
$ apt update
$ apt install -y build-essential python3-venv git

# Get example
$ git clone https://github.com/conan-io/examples2.git
$ cd examples2/examples/tools/cmake/cmake_toolchain/extend_own_cmake_presets

# Install conan and cmake
$ python3 -m venv venv
$ source venv/bin/activate
$ pip install conan cmake

# Configure conan
$ conan profile detect

Detected profile:
...
build_type=Release
...

# Configure project
$ conan install .

# Here the bug : generated preset are invalid
$ cmake --preset conan-default

CMake Error: Could not read presets from /root/examples2/examples/tools/cmake/cmake_toolchain/extend_own_cmake_presets:
Invalid preset: "conan-debug"

Observation

I run conan install with either build_type=Debug and build_type=Release. Presets are ok.

[memsharded]

Hi @AlexandrePTJ

Thanks for your feedback.

Could you please provide a bit more details to be able to reproduce? Something like:

• A minimal conanfile to reproduce
• Making sure starting from a clean folder
• The exact command you are using
• The full output of the command, and the resulting (relevant) contents (the ConanPresets.json should be barely some includes), so if necessary provide the internal xxxx/generators/CMakePresets.json
• The details of the current platform, like conan version

Thanks!

[AlexandrePTJ]

Hi @memsharded , I updated the description.

[memsharded]

I see, the problem is:

# Configure project
$ conan install .

# Here the bug : generated preset are invalid
$ cmake --preset conan-default

You are missing the installation of the Debug configuration, the docs in https://docs.conan.io/2/examples/tools/cmake/cmake_toolchain/extend_own_cmake_presets.html instruct to do:

$ conan install .
$ conan install . -s build_type=Debug

It is necessary to install both Release and Debug, configurations, as the defined user presets depend on both configurations.
CMake presets need the presets to be defined, the CMakePresets.json described in the docs, "inherits": "conan-debug", and this is validated when presets are loaded even if the debug preset is not being used at that point.

I run conan install with either build_type=Debug and build_type=Release. Presets are ok.

Yes, exactly this, this is needed, CMake needs all inherited presets to exist.

So this doesn't seem a bug then, but expected behavior.

[aiyolo]

I think it would be preferable not to generate CMakeUserPreset.json by default, as generating a conan_toolchain.cmake is sufficient for most scenarios.

[memsharded]

I think it would be preferable not to generate CMakeUserPreset.json by default, as generating a conan_toolchain.cmake is sufficient for most scenarios.

This cannot be changed, it would be breaking behavior to many users that depend on this creation by default.

[memsharded]

@AlexandrePTJ did my above comment clarified the issue?