Commit "Change all toString methods to use std::string", d161dc26, relies on format header (c++ 20), this breaks Zephyr target

[kaartee]

The Zephyr SDK for ESP32 doen't use a version of GCC yet which supports <format>.
Hence, FORTE does not build.

[mx990]

The Zephyr SDK v0.18.0-alpha4 includes gcc 14.3.0, which should also fully support <format>. Could you please give it a try and see if this works for you?

[kaartee]

Have you performed any successful west build with the SDK 0.18.0-alpha4? I can't even get it to compile hellp_world for esp32_devkitc/esp32/procpu. I tried the Zephyr branches main as well as collab-sdk-0.18-dev.

CMake Error at E:/Repositories/zephyrproject/zephyr/cmake/modules/FindHostTools.cmake:111 (include):
  include could not find requested file:

    E:/Repositories/zephyrproject/zephyr/cmake/toolchain/zephyr/gnu/generic.cmake

-- Found Dtc: C:/ProgramData/chocolatey/bin/dtc.exe (found suitable version "1.5.0", minimum required is "1.4.6")
-- Found BOARD.dts: E:/Repositories/zephyrproject/zephyr/boards/espressif/esp32_devkitc/esp32_devkitc_procpu.dts
CMake Error at E:/Repositories/zephyrproject/zephyr/cmake/modules/extensions.cmake:4635 (message):
  dt_preprocess() missing required argument: CPP

[mx990]

It works for me with the collab-sdk-0.18-dev branch when explicitly passing the ZEPHYR_TOOLCHAIN_VARIANT on the command line:

west build -p always -b esp32_devkitc/esp32/procpu samples/hello_world -- -DZEPHYR_TOOLCHAIN_VARIANT=zephyr-gnu