What methods do you usually use to diagnose and find errors in code or systems?

For diagnosing and troubleshooting errors in code or systems, I usually use the following methods:

• Logging: adding debug output at key points in the program to understand where the failure occurs.
• Debugger: using gdb or built-in IDE tools for step-by-step execution and variable analysis.
• Memory dump and core file analysis: when the program crashes, examining dumps to identify the cause.
• Checking input data and assumptions: ensuring that the data the program works with is correct.
• Using static analysis and code checking tools: such as cppcheck or clang-tidy to find potential errors.

Example of using gdb:

gdb ./my_program
run
# After the program crashes
bt  # display call stack

This helps quickly locate the error site.