README_troubleshooting.md

Troubleshooting

Update Conan

Many problems that users have can be resolved by updating Conan, so if you are having any trouble with this project, you should start by doing that.

To update conan:

pip install --user --upgrade conan

You may need to use pip3 instead of pip in this command, depending on your platform.

Clear Conan cache

If you continue to have trouble with your Conan dependencies, you can try clearing your Conan cache:

conan remove -f '*'

The next time you run cmake or cmake --build, your Conan dependencies will be rebuilt. If you aren't using your system's default compiler, don't forget to set the CC, CXX, CMAKE_C_COMPILER, and CMAKE_CXX_COMPILER variables, as described in the 'Build using an alternate compiler' section above.

Identifying misconfiguration of Conan dependencies

If you have a dependency 'A' that requires a specific version of another dependency 'B', and your project is trying to use the wrong version of dependency 'B', Conan will produce warnings about this configuration error when you run CMake. These warnings can easily get lost between a couple hundred or thousand lines of output, depending on the size of your project.

If your project has a Conan configuration error, you can use conan info to find it. conan info displays information about the dependency graph of your project, with colorized output in some terminals.

cd build
conan info .

In my terminal, the first couple lines of conan info's output show all of the project's configuration warnings in a bright yellow font.

For example, the package spdlog/1.5.0 depends on the package fmt/6.1.2. If you were to modify the file conanfile.py so that it requires an earlier version of fmt, such as fmt/6.0.0, and then run:

conan remove -f '*'       # clear Conan cache
rm -rf build              # clear previous CMake build
cmake -S . -B ./build     # rebuild Conan dependencies
conan info ./build

...the first line of output would be a warning that spdlog needs a more recent version of fmt.