How to restore the correct operation of gcc?

Question

linux

After installing musl-libc, gcc stopped compiling programs that depended on anything other than the standard library. Removing musl-libc did not fix the errors.
When compiling, it gives error messages.
When trying to compile something using SDL2:

When trying to compile source code generated by GHC:

Answer 1

After installing musl-libc

what kind of linux? how did you install musl-libc?