pr: return correct exit code on error

src/uu/pr/src/pr.rs

@@ -386,13 +386,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let opt_args = recreate_arguments(&args);
 
     let mut command = uu_app();
-    let matches = match command.try_get_matches_from_mut(opt_args) {
-        Ok(m) => m,
-        Err(e) => {
-            e.print()?;
-            return Ok(());
-        }
-    };
+    let matches = command.try_get_matches_from_mut(opt_args)?;
 
     let mut files = matches
         .get_many::<String>(options::FILES)

tests/by-util/test_pr.rs

@@ -43,6 +43,15 @@ fn valid_last_modified_template_vars(from: DateTime<Utc>) -> Vec<Vec<(String, St
         .collect()
 }
 
+#[test]
+fn test_invalid_flag() {
+    new_ucmd!()
+        .arg("--invalid-argument")
+        .fails()
+        .no_stdout()
+        .code_is(1);
+}
+
 #[test]
 fn test_without_any_options() {
     let test_file_path = "test_one_page.log";