Expose version info in CLI tool with build-time obtained git hash (#787)

* version info with built-time obtained git hash

* clippy

* rerun-if-changed properly and handle git command failing

* cargo fmt

cli/src/commands/mod.rs

@@ -5,3 +5,4 @@
 pub mod codegen;
 pub mod compatibility;
 pub mod metadata;
+pub mod version;

cli/src/commands/version.rs

@@ -0,0 +1,16 @@
+use clap::Parser as ClapParser;
+
+/// Prints version information
+#[derive(Debug, ClapParser)]
+pub struct Opts {}
+
+pub fn run(_opts: Opts) -> color_eyre::Result<()> {
+    let git_hash = env!("GIT_HASH");
+    println!(
+        "{} {}-{}",
+        clap::crate_name!(),
+        clap::crate_version!(),
+        git_hash
+    );
+    Ok(())
+}

cli/src/main.rs

@@ -13,6 +13,7 @@ enum Command {
     Metadata(commands::metadata::Opts),
     Codegen(commands::codegen::Opts),
     Compatibility(commands::compatibility::Opts),
+    Version(commands::version::Opts),
 }
 
 #[tokio::main]
@@ -24,5 +25,6 @@ async fn main() -> color_eyre::Result<()> {
         Command::Metadata(opts) => commands::metadata::run(opts).await,
         Command::Codegen(opts) => commands::codegen::run(opts).await,
         Command::Compatibility(opts) => commands::compatibility::run(opts).await,
+        Command::Version(opts) => commands::version::run(opts),
     }
 }