From 98aea3b743f435e8450e2f1a7d2b830b76295dfd Mon Sep 17 00:00:00 2001
From: Tim Bruijnzeels <tim@nlnetlabs.nl>
Date: Tue, 6 Oct 2020 14:06:15 +0200
Subject: [PATCH] Add build.rs which is used to check the Rust version before
 building.

---
 build.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 build.rs

diff --git a/build.rs b/build.rs
new file mode 100644
index 00000000..600f981f
--- /dev/null
+++ b/build.rs
@@ -0,0 +1,14 @@
+extern crate rustc_version;
+use rustc_version::{Version, version};
+
+fn main() {
+    let version = version().expect("Failed to get rustc version.");
+    if version < Version::parse("1.42.0").unwrap() {
+        eprintln!(
+            "\n\nAt least Rust version 1.42 is required.\n\
+             Version {} is used for building.\n\
+             Build aborted.\n\n",
+             version);
+        panic!();
+    }
+}