Breakpoint at the wrong line
Something is wrong with the previous answers.
The optimization option (-O) has a number (0-3). As the number increases, the optimization that the compiler does increases.
When debugging, you want to turn the optimization off (-O0).
When you release your code you want to test and release with higher levels of optimization (-O3).
If your toolchain is set with debug set to 3 and release set to 0, that's just wrong.
Andrei