Rollup merge of rust-lang#83711 - JohnTitor:more-friendly-unknown-tar…

…get-error, r=davidtwco

Clarify `--print target-list` is a rustc's option

Fixes rust-lang#68238

compiler/rustc_session/src/config.rs

@@ -953,7 +953,7 @@ pub fn build_target_config(opts: &Options, target_override: Option<Target>) -> T
             opts.error_format,
             &format!(
                 "Error loading target specification: {}. \
-            Use `--print target-list` for a list of built-in targets",
+                 Run `rustc --print target-list` for a list of built-in targets",
                 e
             ),
         )