I tried to compile and install SDL2 from https://wiki.libsdl.org/Installation. Then I tried to test a program, I got a program file missing error for libsdl2-2.0.so.0: Program file cannot be opened. Pretty normal. Google time! I did some stuff from here: https://stackoverflow.com/questions/29711336/libsdl2-2-0-so-0-cannot-open-shared-object-file. I was trying to fix my problem.
I suddenly got a can't find -lvulkan error from gcc(I was still trying to fix my program file errors). I forgot what I had just done, in my attempts to solve the libsdl2-2.0.so program file error. For now, I removed the -lvulkan, it still didn't work due to the .so file not being found.
Then I ran ldconfig in the terminal, it was a simple solve, then it was running, I have no idea what that does, found I need to do it from Google. SDL worked, but -lvulkan error persisted. SDL_CreateWindow() wasn't working now. It was giving no available video device error. It's probably because of OpenGL stuff from my Google research. You know what? Now, -lGL too doesn't work. No linking against OpenGL after doing whatever I did, probably caused by the same thing that caused Vulkan problems.
Any idea what I might have done? Why is this happening? I only ran a sudo command once for ldconfig, how can any other thing do anything at /usr? I did got problems with the trash in nautilus, seemed like it thought that deleted files still existed. It was fixed after a restart. I had used nautilus with sudo once, that's where it could have gone wrong but my trash was empty, so I surely didn't delete anything.
