Implement warning for ignored trailing arguments

src/bin/cargo/cli.rs

@@ -1,6 +1,7 @@
 use cargo::core::{features, CliUnstable};
 use cargo::{self, drop_print, drop_println, CliResult, Config};
 use clap::{AppSettings, Arg, ArgMatches};
+use itertools::Itertools;
 
 use super::commands;
 use super::list_commands;
@@ -169,6 +170,17 @@ fn expand_aliases(
  cmd,
  ))?;
  }
+ (Some(_), None) => {
+ // Command is built-in and is not conflicting with alias, but contains ignored values.
+ if let Some(mut values) = args.values_of("") {
+ config.shell().warn(format!(
+ "trailing arguments after built-in command `{}` are ignored: `{}`",
+ cmd,
+ values.join(" "),
+ ))?;
+ }
+ }
+ (None, None) => {}
  (_, Some(mut alias)) => {
  alias.extend(
  args.values_of("")
@@ -186,7 +198,6 @@ fn expand_aliases(
  let (expanded_args, _) = expand_aliases(config, new_args)?;
  return Ok((expanded_args, global_args));
  }
- (_, None) => {}
  }
  };
 

tests/testsuite/cargo_alias_config.rs

@@ -192,3 +192,21 @@ fn global_options_with_alias() {
  )
  .run();
 }
+
+#[cargo_test]
+fn weird_check() {
+ let p = project()
+ .file("Cargo.toml", &basic_bin_manifest("foo"))
+ .file("src/main.rs", "fn main() {}")
+ .build();
+
+ p.cargo("-- check --invalid_argument -some-other-argument")
+ .with_stderr(
+ "\
+[WARNING] trailing arguments after built-in command `check` are ignored: `--invalid_argument -some-other-argument`
+[CHECKING] foo v0.5.0 ([..])
+[FINISHED] dev [unoptimized + debuginfo] target(s) in [..]
+",
+ )
+ .run();
+}