How to solve HardFault_Handler problem at debugging?

Generally, look at the call stack to understand where it entered the hard fault. Look at the code around that point and fix it. Step through code, set breakpoints, see if you can pinpoint exactly where it happens.

Don't they teach this in college?

Have your Hard Fault Handler output actionable data to identify the code causing the fault. A while() provides no useful information.

https://github.com/cturvey/RandomNinjaChef/blob/main/KeilHardFault.c

On the Cortex-M0 watch for unaligned pointers, as well as pointers to memory that doesn't exist.

The registers, and the faulting instructions, and those immediately preceding, are usually a good indication of why the processor is unhappy.

If you don't see the call stack deep enough - this can be because the compiler over-optimized HardFault_Handler (and other such handlers there). It sees the while(1), figures out that the function never returns, so there's no need to put the return address on stack. If this is the case - a simple trick can beat the compiler and let you see the stack of HardFault_Handler.