What do you mean? They are CFLAGS that are passed to gcc. They depend on libasan and libubsan. I just think it's cool that you can do that. And some flags can help you catch use after free and other memory related bugs with gcc. It won't error and not compile but you'll get warnings that describe the bug and show where it is in your code and I thought this is cool and all the Rust shill are talking about Rust saying it's something you can't get in C, but you can. I am practicing my C skills right now and reading K&R and doing all the exercise with friends and we discovered all this cool stuff so we can test our programs to catch those bugs.