From bd884d8043b9ebd4e2bbae0e31bc4780d2e26c6a Mon Sep 17 00:00:00 2001
From: "许杰友 Jieyou Xu (Joe)" <39484203+jieyouxu@users.noreply.github.com>
Date: Mon, 24 Feb 2025 20:10:49 +0800
Subject: Prevent `rmake.rs` from using any nightly/unstable features

---
 src/tools/compiletest/src/runtest/run_make.rs | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'src/tools/compiletest')

diff --git a/src/tools/compiletest/src/runtest/run_make.rs b/src/tools/compiletest/src/runtest/run_make.rs
index 8900752bd4b..073116933bd 100644
--- a/src/tools/compiletest/src/runtest/run_make.rs
+++ b/src/tools/compiletest/src/runtest/run_make.rs
@@ -105,6 +105,11 @@ impl TestCx<'_> {
             .expect("stage0 rustc is required to run run-make tests");
         let mut rustc = Command::new(&stage0_rustc);
         rustc
+            // `rmake.rs` **must** be buildable by a stable compiler, it may not use *any* unstable
+            // library or compiler features. Here, we force the stage 0 rustc to consider itself as
+            // a stable-channel compiler via `RUSTC_BOOTSTRAP=-1` to prevent *any* unstable
+            // library/compiler usages, even if stage 0 rustc is *actually* a nightly rustc.
+            .env("RUSTC_BOOTSTRAP", "-1")
             .arg("-o")
             .arg(&recipe_bin)
             // Specify library search paths for `run_make_support`.
-- 
cgit 1.4.1-3-g733a5