Merge pull request #7622 from blyxxyz/flush-bufwriters

Flush `BufWriter`s, clean up error reporting

tests/by-util/test_tail.rs

@@ -4843,3 +4843,13 @@ fn test_child_when_run_with_stderr_to_stdout() {
         .fails()
         .stdout_only(expected_stdout);
 }
+
+#[cfg(target_os = "linux")]
+#[test]
+fn test_failed_write_is_reported() {
+    new_ucmd!()
+        .pipe_in("hello")
+        .set_stdout(std::fs::File::create("/dev/full").unwrap())
+        .fails()
+        .stderr_is("tail: No space left on device\n");
+}