someone broke a mod.rs so i fixed it.

kernel/src/lib.rs

@@ -38,7 +38,9 @@ pub mod prelude {
     pub use crate::{
         eprint, eprintln, print, print_log, println, println_log, serial_print,
         serial_println,
-        std::io::{_print, _print_err, _print_log, _serial_write},
+        debug, debugln,
+        std::io::{_print, _print_log, _serial_write, _print_err},
+        std::debug::_debug,
     };
 }