How to configure a particular GCC cross toolchain

I have imported some source code as C++ Makefile Project to an Eclipse CDT workspace, and specified the Cross GCC toolchain for "Indexer Settings":

The project import went fine, but the include path settings just point to my current native host GCC implementation:

I've been looking in the Toolchain Editor properties dialog, but couldn't find any way to configure a particular cross-toolchain I've been building and installing on my development machine:

The opened dialog only allows to select the toolchain particles, but not to configure, where these should be actually located:

How can I configure Eclipse CDT to use my homebrew GCC cross-toolchain to feed the Indexer correctly, and use the standard include paths supplied by my particular GCC cross-toolchain?

"How can I configure Eclipse CDT to use my homebrew GCC cross-toolchain to feed the Indexer correctly, and use the standard include paths supplied from this GCC cross-toolchain? "

Unfortunately it's not obvious or intuitive, how to set the properties for a particular (cross-)toolchain, that should be bound to a project.

To make these property settings available, first go to the C++ Build/Builder Settings Tab in the project properties dialog:

and check the Generate Makefiles automatically option. Don't click the Apply or OK button now!
But proceed to the C++ Build->Settings sub page

and fill in the cross-toolchain prefix, and path where the binaries are actually located.

Go back to the C++ Build/Builder Settings Tab and uncheck the Generate Makefiles automatically (to prevent unexpected behavior on automatically started builds) option, before saving the project properties.