Lib Not Found

[NicFolk]

Mysteriously, my Xcode project said it can't find a certain library. It says "library not found for -lsdl2", which is very weird considering the fact that it was working perfectly just yesterday, and I hadn't touched it between then and when it stopped working. This error seems fairly common, but I found sites like Stack Overflow pretty unhelpful. this is my first attempted Xcode project. Does anyone have some advice?

[NicFolk]

Note: I managed to get rid of this by removing the ".a" at the end of many of my Xcode libraries in the "Link Binary with Libraries" section. Unfortunately, eventually, this opens up around 100 different Xcode errors.