Why do library paths and libraries, but not include paths, disappear when swapping toolchains?

[jmccabe]

I have a load of projects configured with multiple build configurations, one of them being Debug, which all build using gcc. I've recently been looking at building with llvm/clang to try to take advantage of some of the extra tools that work with clang but not gcc, so I've created a new DebugClang configuration by using the "Manage Configurations..." dialog.

I use the "Paths and Symbols" section of the project properties to configure include paths, library paths and libraries and, just after creating the new configuration, those are all as they were before. However, when I go to the "Tool Chain Editor" and swap to "LLVM with Clang (Linux)", apply it, then go back to the "Paths and Symbols" section, the library and library paths lists are empty, but the include paths that are configured (for GNU C++) are still there.

Is that 'normal'? Is there a way to get the toolchain change to leave the "Paths and Symbols" stuff alone?

BTW - This is Eclipse 2023-12.