If your program cannot say you where is the problem, it is better to invest your time into better code: add more self-diagnostic, constraints, asserts, and automated test cases.

If you waste your time on debugger, then you will have just bug fixed and nothing else.

If you invest your time into code, you will have bug fixed AND much better code.

Computers can catch bugs much faster than humans. Programming is invented for that. Think like you already have programmable debugger inside your program. Invest your time into useful tools, which you can use to trace and check your program.