ST-link printf to console with GDB and semihosting or ITM and ST Link Utility
Great point about the solder joints. I think the new ones come with a low value resistor closing the correct solder bridges. I have both the STM32F072B-DISCO and the STM32F401C-DISCO dev boards and they both already have that low value resistor closing the bridges. Also, check your schematics. There is a possibilitiy you can use a jumper wire to the SWD connector’s SWO line and have it work that way.
Another thing to remind everyone is that if you are making your projects using something other than the ST Cube you might have to include the relevant files manually. That is to say the CMSIS files for the ITM or librdirmon for semihosting.