Development tools for Zephyr on STM32Workbench for Zephyr: VS Code extension to set up, build, flash and debug Zephyr applications on STM32.Devicetree manager: browse, edit and visualize Zephyr devicetree, STM32CubeMX-like for Zephyr.
ihave notice same problem with non ac6 eclipse/cdt (ie cross gcc )
it is likely an eclipse cdt issue.
unfortunatly i have not find any over solution than editing the .cproject and do search/replace of the duplicate path.