Better error instead of show the help

Signed-off-by: hi-rustin <[email protected]>

Author: 0xPoe

src/cli/rustup_mode.rs

@@ -114,13 +114,8 @@ pub fn main() -> Result<utils::ExitCode> {
                 write!(process().stdout().lock(), "{err}")?;
                 return Ok(utils::ExitCode(1));
             }
-            if err.kind() == ValueValidation {
-                if err.to_string().contains(TOOLCHAIN_OVERRIDE_ERROR) {
-                    err!("{TOOLCHAIN_OVERRIDE_ERROR}\n");
-                    cli().print_help()?;
-                } else {
-                    write!(process().stdout().lock(), "{err}")?;
-                }
+            if err.kind() == ValueValidation && err.to_string().contains(TOOLCHAIN_OVERRIDE_ERROR) {
+                write!(process().stderr().lock(), "{err}")?;
                 return Ok(utils::ExitCode(1));
             }
             Err(err)
@@ -258,7 +253,9 @@ pub(crate) fn cli() -> Command<'static> {
                     if s.starts_with('+') {
                         Ok(s.to_owned())
                     } else {
-                        Err(TOOLCHAIN_OVERRIDE_ERROR.to_owned())
+                        Err(format!(
+                            "\"{s}\" is not a valid subcommand, so it was interpreted as a toolchain name, but it is also invalid. {TOOLCHAIN_OVERRIDE_ERROR}"
+                        ))
                     }
                 }),
         )

tests/suite/cli-ui/rustup/rustup_unknown_arg_stdout.toml

@@ -1,51 +1,9 @@
 bin.name = "rustup"
 args = ["random"]
 status.code = 1
-stdout = """
-rustup [..]
-The Rust toolchain installer
-
-USAGE:
-    rustup[EXE] [OPTIONS] [+toolchain] <SUBCOMMAND>
-
-ARGS:
-    <+toolchain>    release channel (e.g. +stable) or custom toolchain to set override
-
-OPTIONS:
-    -v, --verbose    Enable verbose output
-    -q, --quiet      Disable progress output
-    -h, --help       Print help information
-    -V, --version    Print version information
-
-SUBCOMMANDS:
-    show           Show the active and installed toolchains or profiles
-    update         Update Rust toolchains and rustup
-    check          Check for updates to Rust toolchains and rustup
-    default        Set the default toolchain
-    toolchain      Modify or query the installed toolchains
-    target         Modify a toolchain's supported targets
-    component      Modify a toolchain's installed components
-    override       Modify directory toolchain overrides
-    run            Run a command with an environment configured for a given toolchain
-    which          Display which binary will be run for a given command
-    doc            Open the documentation for the current toolchain
-...
-    self           Modify the rustup installation
-    set            Alter rustup settings
-    completions    Generate tab-completion scripts for your shell
-    help           Print this message or the help of the given subcommand(s)
-
-DISCUSSION:
-    Rustup installs The Rust Programming Language from the official
-    release channels, enabling you to easily switch between stable,
-    beta, and nightly compilers and keep them updated. It makes
-    cross-compiling simpler with binary builds of the standard library
-    for common platforms.
-
-    If you are new to Rust consider running `rustup doc --book` to
-    learn Rust.
-"""
+stdout = ""
 stderr = """
-error: To override the toolchain using the 'rustup +toolchain' syntax, make sure to prefix the toolchain override with a '+'
+error: Invalid value \"random\" for '<+toolchain>': \"random\" is not a valid subcommand, so it was interpreted as a toolchain name, but it is also invalid. To override the toolchain using the 'rustup +toolchain' syntax, make sure to prefix the toolchain override with a '+'
 
+For more information try --help
 """

tests/suite/cli_misc.rs

@@ -946,7 +946,10 @@ fn override_by_toolchain_on_the_command_line() {
         );
         config.expect_err(
             &["rustup", "@stable", "which", "rustc"],
-            r#"Invalid value "@stable" for '<+toolchain>': Toolchain overrides must begin with '+'"#,
+            "Invalid value \"@stable\" for '<+toolchain>': \"@stable\" is not a valid subcommand, \
+            so it was interpreted as a toolchain name, but it is also invalid. \
+            To override the toolchain using the 'rustup +toolchain' syntax, \
+            make sure to prefix the toolchain override with a '+'",
         );
         config.expect_stderr_ok(
             &["rustup", "+stable", "set", "profile", "minimal"],