xtensa-esp32-elf-gdb & openOCD usage

Does anyone have instructions on how to connect GDB? I'm doing this through expansion3 board, so that is probably my first problem.

My JTAG connetion: https://gist.github.com/cmisztur/4bb576f6bb550067029abe24eef7c274

Steps to reproduce:

cd ~/esp/pycom-esp-idf/examples/wifi/scan
make menuconfig
# Compiler --> Optimization Level = Debug
make -j8 clean
make -j8 all
cd ~/esp/pycom-micropython-sigfox/esp32
python get_idf_libs.py --idflibs $IDF_PATH/examples/wifi/scan/build
#cd ../mpy-cross
#make -j8 clean
#make -j8 all
#cd ../esp32
# ??? make -j8 erase
make BOARD=LOPY -j8 clean
make BOARD=LOPY -j8 TARGET=boot
make BOARD=LOPY -j8 TARGET=app
make BOARD=LOPY -j8 flash

Result:

$ bin/openocd -s share/openocd/scripts -f interface/jlink.cfg -f board/esp-wroom-32.cfg
Open On-Chip Debugger 0.10.0-dev (2018-09-20-12:54)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html
adapter speed: 20000 kHz
esp32 interrupt mask on
Info : No device selected, using first device.
Info : J-Link V9 compiled Aug 23 2018 09:45:44
Info : Hardware version: 9.40
Info : VTarget = 3.301 V
Info : Reduced speed from 20000 kHz to 15000 kHz (maximum).
Info : Reduced speed from 20000 kHz to 15000 kHz (maximum).
Info : clock speed 20000 kHz
Error: JTAG scan chain interrogation failed: all zeroes
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Error: esp32.cpu0: IR capture error; saw 0x00 not 0x01
Warn : Bypassing JTAG setup events due to errors
cpu0: Current bits set: none
cpu1: Current bits set: none

pycom / pycom-micropython-sigfox

xtensa-esp32-elf-gdb & openOCD usage #223