fix(alias): add test

src/bin/cargo/cli.rs

@@ -279,9 +279,6 @@ fn expand_aliases(
     args: ArgMatches,
     mut already_expanded: Vec<String>,
 ) -> Result<(ArgMatches, GlobalArgs), CliError> {
-    println!("gctx == {:#?}", gctx);
-    println!("args == {:#?}", args);
-
     if let Some((cmd, sub_args)) = args.subcommand() {
         let exec = commands::builtin_exec(cmd);
         let aliased_cmd = super::aliased_command(gctx, cmd);
@@ -359,9 +356,11 @@ For more information, see issue #12207 <https://github.com/rust-lang/cargo/issue
                 let global_args = GlobalArgs::new(sub_args);
                 let new_args = cli(gctx).no_binary_name(true).try_get_matches_from(alias)?;
 
-                let new_cmd = match new_args.subcommand_name() {
-                    Some(new_cmd) => new_cmd,
-                    None => return Err(anyhow!("subcommand is required, add a subcommand to the command alias {cmd} .").into()),
+                let Some(new_cmd) = new_args.subcommand_name() else {
+                    return Err(anyhow!(
+                        "subcommand is required, add a subcommand to the command alias `alias.{cmd}`"
+                    )
+                        .into());
                 };
 
                 already_expanded.push(cmd.to_string());

tests/testsuite/cargo_alias_config.rs

@@ -463,3 +463,27 @@ fn empty_alias() {
         )
         .run();
 }
+
+#[cargo_test]
+fn alias_no_subcommand() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file("src/main.rs", "fn main() {}")
+        .file(
+            ".cargo/config.toml",
+            r#"
+               [alias]
+               a = "--locked"
+            "#,
+        )
+        .build();
+
+    p.cargo("a")
+        .with_status(101)
+        .with_stderr(
+            "\
+[ERROR] subcommand is required, add a subcommand to the command alias `alias.a`
+",
+        )
+        .run();
+}