add git commit hash when hovering version info

build.rs

@@ -8,4 +8,16 @@ fn main() {
         .set_icon("assets/icon.ico")
         .compile()
         .unwrap();
+    println!(
+        "cargo:rustc-env=LATEST_GIT_COMMIT_HASH={}",
+        latest_git_commit_hash()
+    )
+}
+
+fn latest_git_commit_hash() -> String {
+    let git_rev_parse = std::process::Command::new("git")
+        .args(&["rev-parse", "--short=8", "HEAD"])
+        .output()
+        .unwrap();
+    String::from_utf8(git_rev_parse.stdout).unwrap()
 }

src/gui/app.rs

@@ -236,7 +236,8 @@ impl App {
                     if cfg!(debug_assertions) {
                         ui.label("(dev)");
                     }
-                    ui.label(format!("v{}", env!("CARGO_PKG_VERSION")));
+                    ui.label(format!("v{}", env!("CARGO_PKG_VERSION")))
+                        .on_hover_text(env!("LATEST_GIT_COMMIT_HASH"));
                     ui.scope(|ui| {
                         ui.style_mut().spacing.button_padding = egui::Vec2::new(3.0, 0.0);
                         let button = ui