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.
I eventually made it work, I also have a Wellon VP-590 EPROM/FLASH programmer, unplugging the usb lead from the Wellon made the ST-link work again. really odd.