Save and log build commit

Signed-off-by: Evan Lloyd New-Schmidt <evan@new-schmidt.com>

build.rs

@@ -0,0 +1,32 @@
+use std::process::Command;
+
+/// Pass git-describe through CARGO_GIT_VERSION env variable
+///
+/// NOTE: Cargo.toml still needs to be updated on releases
+fn set_version_from_git() {
+    let cmd = Command::new("git")
+        .arg("describe")
+        .arg("--always")
+        .arg("--dirty")
+        .arg("--tags")
+        .output();
+
+    match cmd {
+        Ok(output) if output.status.success() => {
+            let version = String::from_utf8_lossy(&output.stdout);
+            let version = version.trim();
+            println!("cargo:rustc-env=CARGO_GIT_VERSION={}", version);
+            // rerun when git checks out another ref or any ref changes
+            println!("cargo:rerun-if-changed=.git/refs/");
+            println!("cargo:rerun-if-changed=.git/HEAD");
+        }
+        _ => {
+            // crates.io builds without git, so ignore here
+            eprintln!("git describe failed; ignoring");
+        }
+    }
+}
+
+fn main() {
+    set_version_from_git();
+}

src/main.rs

@@ -15,11 +15,24 @@ use om_wikiparser::{
     wm::{parse_wikidata_file, parse_wikipedia_file, Page, WikipediaTitleNorm},
 };
 
+/// Get the version returned by `git describe`, e.g.:
+/// - `v2.0` if a git tag
+/// - the commit hash `034ac04` if not a tag
+/// - `034ac04-dirty` if uncommited changes are present,
+/// or the crate version if not available (if installed from crates.io).
+///
+/// See `build.rs` file for more info.
+fn version() -> &'static str {
+    option_env!("CARGO_GIT_VERSION")
+        .or(option_env!("CARGO_PKG_VERSION"))
+        .unwrap_or("unknown")
+}
+
 /// Extract article HTML from Wikipedia Enterprise HTML dumps.
 ///
 /// Expects an uncompressed dump connected to stdin.
 #[derive(Parser)]
-#[command(version)]
+#[command(version = crate::version())]
 struct Args {
     /// Directory to write the extracted articles to.
     output_dir: PathBuf,
@@ -174,6 +187,8 @@ fn main() -> anyhow::Result<()> {
         .exit()
     }
 
+    info!("{} {}", Args::command().get_name(), version());
+
     let wikipedia_titles = if let Some(path) = args.wikipedia_urls {
         info!("Loading article urls from {path:?}");
         let urls = parse_wikipedia_file(path)?;