tail: update README

src/uu/tail/README.md

@@ -2,6 +2,10 @@
 
 ## Missing features
 
+The `-F` flag (same as `--follow=name --retry`) has very good support on Linux (inotify backend),
+works good enough on macOS/BSD (kqueue backend) with some minor tests not working,
+and is fully untested on Windows.
+
 ### Flags with features
 
 - [x] fast poll := '-s.1 --max-unchanged-stats=1'

src/uu/tail/src/tail.rs

@@ -49,11 +49,11 @@ use uucore::ringbuffer::RingBuffer;
 #[cfg(unix)]
 use crate::platform::stdin_is_pipe_or_fifo;
 #[cfg(unix)]
+use std::fs::metadata;
+#[cfg(unix)]
 use std::os::unix::fs::MetadataExt;
 #[cfg(unix)]
 use std::os::unix::prelude::FileTypeExt;
-#[cfg(unix)]
-use std::fs::metadata;
 
 const ABOUT: &str = "\
                      Print the last 10 lines of each FILE to standard output.\n\

tests/by-util/test_tail.rs

@@ -1416,6 +1416,7 @@ fn test_follow_inotify_only_regular() {
     assert_eq!(buf_stderr, "".to_string());
 }
 
+#[cfg(unix)]
 fn take_stdout_stderr(p: &mut std::process::Child) -> (String, String) {
     let mut buf_stdout = String::new();
     let mut p_stdout = p.stdout.take().unwrap();