Dynamic Printf Debugging with GDB (abstractexpr.com)

The debugger also lets you run a decent amount of code in it, making something of a REPL of sorts. You can modify the state of the program and see what it does in response without having to recompile your code.

Tracepoints/logpoints have been a part of pretty much any debugger for a long time now: https://debugagent.com/the-best-way-to-diagnose-a-patient-is...