The next option is the debug information. This does not directly affect performance, but it's an interesting configuration item. In this case, you can decide if the debug symbol information gets added to the final executable. This is really useful if you are developing, and especially if you are using a debugger such as GDB. Adding debug information to the executable will enable you to get the function names and even the line numbers of each instruction being executed in the processor. This will give you great insight about what is happening in the code.

In any case, debug information is not so useful in final release binaries, as final release binaries are not meant to be used in debugging. And the debug information usually adds a lot of size to the final binary. This has many times been a concern among developers, as the size of Rust binaries is usually much bigger than the ones written in C/C++. This is in part due to this configuration, and in most cases due to the panic behavior, which we will check later. Debug symbols will also show information about the original code, so it might make sense to hide it in closed-source projects.

To avoid extra debug symbols in the final binary, the debug option must be set to false. This can be done for each profile, and by default, it's true only for the development profile. If you'd like to enable it for testing also, for example, you can add this in the Cargo.toml file:

    [profile.test]
    debug = true

You can, of course, combine this with any other profile option:

    [profile.test]
    debug = true
    opt-level = 1