From ce6adccdade1ec29bff031c296c5ae0d80ab0446 Mon Sep 17 00:00:00 2001
From: Thom Chiovoloni <thom@shift.click>
Date: Sun, 12 Mar 2023 00:23:28 -0800
Subject: [PATCH] Prevent stable `libtest` from supporting `-Zunstable-options`

---
 src/bootstrap/compile.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 8b80dfc0f9b97..54971af644c28 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -339,6 +339,12 @@ pub fn std_cargo(builder: &Builder<'_>, target: TargetSelection, stage: u32, car
         ""
     };
 
+    // `libtest` uses this to know whether or not to support
+    // `-Zunstable-options`.
+    if !builder.unstable_features() {
+        cargo.env("CFG_DISABLE_UNSTABLE_FEATURES", "1");
+    }
+
     let mut features = String::new();
 
     // Cranelift doesn't support `asm`.