chore(vendor): add anyhow crate

third_party/crates/clap-4.6.7/examples/multicall-busybox.rs

@@ -0,0 +1,47 @@
+use std::path::PathBuf;
+use std::process::exit;
+
+use clap::{Arg, ArgAction, Command, value_parser};
+
+fn applet_commands() -> [Command; 2] {
+    [
+        Command::new("true").about("does nothing successfully"),
+        Command::new("false").about("does nothing unsuccessfully"),
+    ]
+}
+
+fn main() {
+    let cmd = Command::new(env!("CARGO_CRATE_NAME"))
+        .multicall(true)
+        .subcommand(
+            Command::new("busybox")
+                .arg_required_else_help(true)
+                .subcommand_value_name("APPLET")
+                .subcommand_help_heading("APPLETS")
+                .arg(
+                    Arg::new("install")
+                        .long("install")
+                        .help("Install hardlinks for all subcommands in path")
+                        .exclusive(true)
+                        .action(ArgAction::Set)
+                        .default_missing_value("/usr/local/bin")
+                        .value_parser(value_parser!(PathBuf)),
+                )
+                .subcommands(applet_commands()),
+        )
+        .subcommands(applet_commands());
+
+    let matches = cmd.get_matches();
+    let mut subcommand = matches.subcommand();
+    if let Some(("busybox", cmd)) = subcommand {
+        if cmd.contains_id("install") {
+            unimplemented!("Make hardlinks to the executable here");
+        }
+        subcommand = cmd.subcommand();
+    }
+    match subcommand {
+        Some(("false", _)) => exit(1),
+        Some(("true", _)) => exit(0),
+        _ => unreachable!("parser should ensure only valid subcommand names are used"),
+    }
+}