From 7760f8ec4297fc9a8bf319ffefff02ba9b17458c Mon Sep 17 00:00:00 2001
From: Deadbeef <ent3rm4n@gmail.com>
Date: Thu, 19 Jun 2025 18:31:56 +0800
Subject: [PATCH] add comment to `src/bootstrap/build.rs`

---
 src/bootstrap/build.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/bootstrap/build.rs b/src/bootstrap/build.rs
index e0e32d3135354..d9810e899a043 100644
--- a/src/bootstrap/build.rs
+++ b/src/bootstrap/build.rs
@@ -1,6 +1,7 @@
 use std::env;
 
 fn main() {
+    // this is needed because `HOST` is only available to build scripts.
     let host = env::var("HOST").unwrap();
     println!("cargo:rerun-if-changed=build.rs");
     println!("cargo:rustc-env=BUILD_TRIPLE={host}");