error[E0583]: file not found for module `lib`
  --> $DIR/special_module_name.rs:1:1
   |
LL | mod lib;
   | ^^^^^^^^
   |
   = help: to create the module `lib`, create file "$DIR/lib.rs" or "$DIR/lib/mod.rs"

error[E0583]: file not found for module `main`
  --> $DIR/special_module_name.rs:4:1
   |
LL | mod main;
   | ^^^^^^^^^
   |
   = help: to create the module `main`, create file "$DIR/main.rs" or "$DIR/main/mod.rs"

warning: found module declaration for lib.rs
  --> $DIR/special_module_name.rs:1:1
   |
LL | mod lib;
   | ^^^^^^^^
   |
   = note: lib.rs is the root of this crate's library target
   = help: to refer to it from other targets, use the library's name as the path
   = note: `#[warn(special_module_name)]` on by default

warning: found module declaration for main.rs
  --> $DIR/special_module_name.rs:4:1
   |
LL | mod main;
   | ^^^^^^^^^
   |
   = note: a binary crate cannot be used as library

error: aborting due to 2 previous errors; 2 warnings emitted

For more information about this error, try `rustc --explain E0583`.