Using FetchContent: Issues with debug postfix

[robamu]

Describe the bug When using FetchContent to install Catch2 like this:

        message(STATUS "Catch2 installation not found. Downloading Catch2 library with FetchContent")
        include(FetchContent)

        FetchContent_Declare(
            Catch2
            GIT_REPOSITORY https://github.com/catchorg/Catch2.git
            GIT_TAG        v3.0.0-preview5
        )

        FetchContent_MakeAvailable(Catch2)

there is an issue when building our unit tests:

gmake[3]: *** No rule to make target '_deps/catch2-build/src/libCatch2d.a', needed by 'fsfw-tests'.  Stop.
gmake[3]: *** Waiting for unfinished jobs....

Also happens on v3.0.0-preview4. Our unittest is built with DEBUG flags to allow stepping. These flags are of course passed to Catch2, and there appears to be an issue with the according target name.

A solution for this was to add the following lines in our CMakeLists.txt

        # set_target_properties(Catch2 PROPERTIES DEBUG_POSTFIX "")

Reproduction steps Use FetchContent to fetch Catch2 and build your unit test binary in DEBUG mode

Platform information:

• OS: Ubuntu 21.10
• Compiler+version: GCC v11.2.0
• Catch version: v3.0.0-preview4 and v3.0.0-preview5

I just wonder if this is

1. A documentation thing by documenting the DEBUG_POSTFIX quickfix when building debug
2. Can be fixed by changing something in the CMakeLists.txt of Catch2
3. Can be fixed by changing the way FetchContent is used