error[E0583]: file not found for module `not_a_real_file` --> $DIR/mod_file_not_exist.rs:3:1 | LL | mod not_a_real_file; | ^^^^^^^^^^^^^^^^^^^^ | = help: to create the module `not_a_real_file`, create file "$DIR/not_a_real_file.rs" or "$DIR/not_a_real_file/mod.rs" error[E0433]: failed to resolve: use of undeclared crate or module `mod_file_aux` --> $DIR/mod_file_not_exist.rs:7:16 | LL | assert_eq!(mod_file_aux::bar(), 10); | ^^^^^^^^^^^^ use of undeclared crate or module `mod_file_aux` error: aborting due to 2 previous errors Some errors have detailed explanations: E0433, E0583. For more information about an error, try `rustc --explain E0433`.