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.
In the meantime (long ago) I figured out that openOCD can write trace messages into a text file. Append the following lines to the user defined debugger script:
tpiu config internal /path/to/debug.txt uart off 8000000
itm port 0 on