Will an uninitialized local variable in C++ 11 lead to not compile?

The thing is that, on my environment (wsl+ubuntu+vscode), I’m writing my xxx.h file for an homework assignment, where I have an uninitialized local variable which will definitely not affect the function (just a debug counter). And using the same MAKEFILE the grader use, I’ve always been available to compile (and my VScode didn’t even show an warning for that), however in grader’s environment it doesn’t. Is that a reason for that?

I expect a reason why the outcome will be different