Update src/lib.rs

Improve error messages.

Co-authored-by: Emil Gardström <emil.gardstrom@gmail.com>

Author: Alexhuszagh

src/lib.rs

@@ -367,9 +367,8 @@ fn warn_on_failure(target: &Target, toolchain: &str, msg_info: MessageInfo) -> R
         if component.is_not_available() {
             shell::warn(format!("rust-std is not available for {target}"), msg_info)?;
             shell::note(
-                "you may need to build components for the std library `-Z build-std=<components>`
-              the available components are core, std, alloc, and proc_macro
-              if no components are provided, cargo will build all components",
+                format_args!(r#"you may need to build components for the target via `-Z build-std=<components>` or in your cross configuration specify `target.{target}.build-std`
+              the available components are core, std, alloc, and proc_macro"#),
                 msg_info,
             )?;
         }