Qt Creator by default is using a temporary directory to configure a CMake project, and afterwards switches to the final build directory when you build the project or add custom parameters to the configuration.

This effectively configures the project twice. For big projects this can take a while and confuses users.

This can be disabled in Qt Creator's settings for CMake - "Auto-create build directories".

This was thought as a feature for the user not to get directories everywhere for CMake projects like Qt Examples.

By not using the /tmp directory we can have a simpler code base, and we could ask the user if it would want to have a build directory to be deleted.