cannot connect with GDB/openOCD but no problem with STM32CubeProgrammer

[b.a.]

I have a strange problem

I use sloeber, an eclipse arduino "plugin" and up to now that worked fine.

Now I wanted to debug a custom STM32L412KB board and I can't connect to the MCU.

I always get an error message that the MCU cannot be found

xPack Open On-Chip Debugger 0.12.0+dev-01557-gdd1758272-dirty (2024-04-02-07:27)
Licensed under GNU GPL v2
For bug reports, read
	http://openocd.org/doc/doxygen/bugs.html
Info : auto-selecting first available session transport "hla_swd". To override use 'transport select <transport>'.
Info : The selected transport took over low-level target control. The results might differ compared to plain JTAG/SWD
Started by GNU MCU Eclipse
Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 500 kHz
Info : STLINK V2J43M28 (API v2) VID:PID 0483:374B
Info : Target voltage: 3.242904
Error: init mode failed (unable to connect to the target)

the debugger is a STM32L4R5 eval board

but connecting/erasing/flashing with STM32CubeProgrammer works fine with the very same setup

I use the same SW stack to debug custom STM32L4R5 boards, but this time with a STLINK-V3MINIE
I am not familiar with GDB/openOCD, up to now it just worked almost out of the box

any hint appreciated!

[Imen.D]

Hello @b.a. 

Make sure to upgrade your firmware and use latest release of STM32CubeProgrammer.

Check your connectivity pins and jumper on the board and try  "Connect Under Reset" mode.