ST-Link clone has SWDIO/SWCLK pins swapped
An ST-Link clone from eBay has its SWCLK and SWDIO pins swapped !
It took me hours to figure that out.
The internal PCB has the right signal names, but the signal names printed on the aluminum housing are wrong.
When using pin2 as SWDIO and pin 4 as SWCLK, it works fine with gdb via SWD using openOCD or with stlink.
See pictures below.