fix(install): improve the error output when the test is failing

tests/by-util/test_install.rs

@@ -352,11 +352,19 @@ fn test_install_copy_file() {
 #[test]
 #[cfg(target_os = "linux")]
 fn test_install_target_file_dev_null() {
-    let (at, mut ucmd) = at_and_ucmd!();
+    let scene = TestScenario::new(util_name!());
+    let at = &scene.fixtures;
+
     let file1 = "/dev/null";
     let file2 = "target_file";
 
-    ucmd.arg(file1).arg(file2).succeeds().no_stderr();
+    let result = scene.ucmd().arg(file1).arg(file2).run();
+
+    println!("stderr = {:?}", result.stderr);
+    println!("stdout = {:?}", result.stdout);
+
+    assert!(result.success);
+
     assert!(at.file_exists(file2));
 }