Eclipse C/C++ environment compiles without problems but the editor reports errors

Question

Since the Eclipse Forums have apparently been discontinued and it is not clear where I can now ask questions about using Eclipse, I put my question here.

I am using the C/C++ environment of Eclipse 2024-12 on a Fedora 41 machine. All my C++ projects are based on CMake and as builder I use ninja. Updates are always installed.

It has long been the case that the editor warns of errors but nevertheless my code compiles without problems. I have seen several posts about this but most of them are many years old and the proposed solutions usually assume dialogs that have long since been replaced by newer dialogs. I notice that routinely all includes of system header files (those, between <>) result in an Unresolved inclusion: <header-name>. The symbols that are used result in a Symbol <symbol-name> could not be resolved.

I know that in Project -> Properties the option is sometimes offered to define C/C++ Symbols and paths. (I think this depends on how you create a new project. When manually using the command cmake -S . -B Build/Debug --fresh --preset=dev-linux -DCMAKE_EXPORT_COMPILE_COMMANDS=1 -DCMAKE_BUILD_TYPE=Debug -G Ninja to create a project, this option is missing).

My question is if in the meantime there is a solution to this problem? The option define C/C++ Symbols and paths is not always available and when available, I don't know which paths or symbols I have to define (I can't find any documentation)

Ben