split: bad error message

src/uu/split/src/split.rs

@@ -1573,7 +1573,10 @@ fn split(settings: &Settings) -> UResult<()> {
         }
         Strategy::Lines(chunk_size) => {
             let mut writer = LineChunkWriter::new(chunk_size, settings)?;
-            copy(&mut reader, &mut writer)
+            match io::copy(&mut reader, &mut writer) {
+                Ok(_) => Ok(()),
+                Err(e) => Err(USimpleError::new(1, format!("{e}"))),
+            }
         }
         Strategy::Bytes(chunk_size) => {
             let mut writer = ByteChunkWriter::new(chunk_size, settings)?;

tests/by-util/test_split.rs

@@ -2068,3 +2068,12 @@ fn test_split_directory_already_exists() {
         .no_stdout()
         .stderr_is("split: 'xaa': Is a directory\n");
 }
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_io_error() {
+    new_ucmd!()
+        .arg("/proc/self/mem")
+        .fails_with_code(1)
+        .stderr_contains("(os error 5)\n");
+}