constants: use build-time COMMIT env var

build.rs

@@ -5,6 +5,8 @@
 // pre-compiled bytes using [include_bytes!()] on the images in [images/].
 #[cfg(windows)]
 fn main() -> std::io::Result<()> {
+	set_commit_env();
+
 	static_vcruntime::metabuild();
 	let mut res = winres::WindowsResource::new();
 	// This sets the icon.
@@ -27,4 +29,22 @@ fn main() -> std::io::Result<()> {
 }
 
 #[cfg(unix)]
-fn main() {}
+fn main() {
+	set_commit_env();
+}
+
+// Set the current git commit to the env var [COMMIT].
+fn set_commit_env() {
+	println!("cargo:rerun-if-changed=.git/refs/heads/");
+
+	let output = std::process::Command::new("git")
+		.args(["rev-parse", "HEAD"])
+		.output()
+		.unwrap();
+
+	let commit = String::from_utf8(output.stdout).unwrap();
+
+	assert!(commit.len() >= 40);
+
+	println!("cargo:rustc-env=COMMIT={commit}");
+}

src/constants.rs

@@ -18,7 +18,7 @@
 pub const GUPAX_VERSION:  &str = concat!("v", env!("CARGO_PKG_VERSION")); // e.g: v1.0.0
 pub const P2POOL_VERSION: &str = "v3.7";
 pub const XMRIG_VERSION:  &str = "v6.20.0";
-pub const COMMIT:         &str = include_str!("../.git/refs/heads/main");
+pub const COMMIT:         &str = env!("COMMIT"); // set in build.rs
 // e.g: Gupax_v1_0_0
 // Would have been [Gupax_v1.0.0] but P2Pool truncates everything after [.]
 pub const GUPAX_VERSION_UNDERSCORE: &str = concat!(