Add version command

src/main.rs

@@ -30,8 +30,11 @@ fn panic_cb(panic: &panic::PanicHookInfo) {
 
     eprintln!(
         "{}",
-        "This is a bug in luby. Please kindly report this at https://git.lua.re/luaneko/luby."
-            .yellow()
+        format_args!(
+            "This is a bug in luby. Please kindly report this at {}.",
+            env!("CARGO_PKG_REPOSITORY")
+        )
+        .yellow()
     );
 }
 
@@ -45,7 +48,7 @@ struct Args {
     #[clap(long, short = 'e', value_name = "CHUNK")]
     eval: Vec<String>,
 
-    /// Libraries to require on startup.
+    /// Libraries to require.
     #[clap(long, short = 'l', value_name = "NAME")]
     lib: Vec<String>,
 
@@ -54,29 +57,45 @@ struct Args {
     log: tracing::Level,
 
     /// LuaJIT control commands.
-    #[clap(long, short = 'j', value_name = "CMD=FLAGS")]
+    #[clap(long, short = 'j', help_heading = "Runtime", value_name = "CMD=FLAGS")]
     jit: Vec<String>,
 
-    /// Number of tokio worker threads.
-    #[clap(long, value_name = "THREADS", default_value_t = Self::threads())]
+    /// Number of worker threads.
+    #[clap(
+        long,
+        short = 'T',
+        help_heading = "Runtime",
+        value_name = "THREADS",
+        default_value_t = Self::threads()
+    )]
     threads: NonZero<usize>,
 
-    /// Number of tokio blocking threads.
-    #[clap(long, value_name = "THREADS", default_value_t = Self::blocking_threads())]
+    /// Number of blocking threads.
+    #[clap(
+        long,
+        help_heading = "Runtime",
+        value_name = "THREADS",
+        default_value_t = Self::blocking_threads()
+    )]
     blocking_threads: NonZero<usize>,
 
     /// Enable tokio-console integration.
-    #[clap(long)]
+    #[clap(long, help_heading = "Debugging")]
     enable_console: bool,
 
     /// tokio-console publish address.
     #[clap(
         long,
+        help_heading = "Debugging",
         value_name = "ADDRESS",
         default_value = "127.0.0.1:6669",
         requires = "enable_console"
     )]
     console_addr: SocketAddr,
+
+    /// Print version.
+    #[clap(long, short = 'V')]
+    version: bool,
 }
 
 impl Args {
@@ -100,6 +119,10 @@ fn main() -> Result<(), ExitCode> {
     panic::set_hook(Box::new(panic_cb));
 
     let args = Args::parse();
+    if args.version {
+        return Ok(print_version());
+    }
+
     init_logger(&args);
 
     let tokio = init_tokio(&args);
@@ -112,6 +135,18 @@ fn main() -> Result<(), ExitCode> {
     })
 }
 
+fn print_version() {
+    println!("luby {}", env!("VERGEN_GIT_DESCRIBE"));
+    println!("{}\n", env!("CARGO_PKG_HOMEPAGE"));
+    println!("Compiled with {} -- {}", luajit::version(), luajit::url());
+    println!(
+        "Compiled with rustc {} on {} for {}",
+        env!("VERGEN_RUSTC_SEMVER"),
+        env!("VERGEN_RUSTC_HOST_TRIPLE"),
+        env!("VERGEN_CARGO_TARGET_TRIPLE"),
+    );
+}
+
 fn init_logger(args: &Args) {
     use tracing::level_filters::LevelFilter;
     use tracing_subscriber::{Layer, util::*};