Xcode unable to find header files? Make sure you use the correct slash

So, I was porting my game from windows to mac, and kept running into this issue when attempting to build:

‘GameFramework\CharacterMovementComponent.h’ file not found

“What do you mean, not found?” I said. “It’s right there!”
Well, after an hour or two of fruitlessly searching around for a solution, I realized that all my other includes used /, not the other one. Turns out, while Windows apparently doesn’t care about that, Mac definitely does. I changed it, and everything is working fine.

So. Don’t be like me. Use /.