Exporting without installation

How can we make the targets of project A available to the consuming project B? Usually, we'd reach for the find_package() command, but that would mean that we'd need to create a package and install it on the system. That approach is useful, but it takes some work. Sometimes, we just need a really quick way to build a project and make its targets available for other projects.

We could save some time by including the main listfile of A: it contains all the target definitions already. Unfortunately, it also potentially contains a lot of other things: global configuration, requirements, CMake commands with side effects, additional dependencies, and perhaps targets that we don't want in B (such as unit tests). So, let's not do that. It's better to achieve this by providing a target export file that the consuming project, B, can include with the include() command:

cmake_minimum_required(VERSION 3.20.0)
project(B)
include(/path...