--version should just print the command name, not the path

This will fix the parsing for old autoconf
Closes: uutils#8880

Author: sylvestre

src/uucore/src/lib/lib.rs

@@ -328,7 +328,14 @@ static UTIL_NAME: LazyLock<String> = LazyLock::new(|| {
     let is_man = usize::from(ARGV[base_index].eq("manpage"));
     let argv_index = base_index + is_man;
 
-    ARGV[argv_index].to_string_lossy().into_owned()
+    // Strip directory path to show only utility name
+    // (e.g., "mkdir" instead of "./target/debug/mkdir")
+    // in version output, error messages, and other user-facing output
+    std::path::Path::new(&ARGV[argv_index])
+        .file_name()
+        .unwrap_or(&ARGV[argv_index])
+        .to_string_lossy()
+        .into_owned()
 });
 
 /// Derive the utility name.

tests/by-util/test_mkdir.rs

@@ -24,6 +24,17 @@ fn test_invalid_arg() {
     new_ucmd!().arg("--definitely-invalid").fails_with_code(1);
 }
 
+#[test]
+fn test_version_no_path() {
+    let result = new_ucmd!().arg("--version").succeeds();
+    let stdout = result.stdout_str();
+
+    assert!(stdout.starts_with("mkdir (uutils coreutils)"));
+
+    let first_line = stdout.lines().next().unwrap();
+    assert!(!first_line.starts_with("./") && !first_line.starts_with('/'));
+}
+
 #[test]
 fn test_no_arg() {
     new_ucmd!()