feat: git-based nightly versions

build.rs

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: Prosperity-3.0.0
+// Copyright Scientific Computing Studio
+// Source: https://git.scient.ing/education/coursebank
+
+//! Chooses the version string compiled into the binary.
+//!
+//! Normal and release builds use the version from `Cargo.toml`. Nightly builds
+//! set `COURSEBANK_VERSION` (to a git-derived string; see
+//! `scripts/nightly-version.sh`) so `coursebank --version` reflects how far the
+//! build is past the last release rather than an unreleased number.
+
+use std::env;
+
+fn main() {
+    let version = match env::var("COURSEBANK_VERSION") {
+        Ok(v) if !v.trim().is_empty() => v,
+        _ => env::var("CARGO_PKG_VERSION").expect("cargo always sets CARGO_PKG_VERSION"),
+    };
+    println!("cargo:rustc-env=COURSEBANK_VERSION={version}");
+    println!("cargo:rerun-if-env-changed=COURSEBANK_VERSION");
+    println!("cargo:rerun-if-env-changed=CARGO_PKG_VERSION");
+}