Print one line per env var

Author: oli-obk

cargo-miri/bin.rs

@@ -911,7 +911,7 @@ fn phase_rustc(mut args: env::Args, phase: RustcPhase) {
                 }
             }
             for (key, value) in envs {
-                eprint!("{key}={value:?} ");
+                eprintln!("{key}={value:?} \\");
             }
         }
         eprintln!("{:?}", cmd);