From 34c1a21f35d317c51a0ea075bee1368bf3d86b6b Mon Sep 17 00:00:00 2001
From: Ben Kimock <kimockb@gmail.com>
Date: Sun, 28 Jun 2026 23:30:36 -0400
Subject: [PATCH] [perf] set debug builds to mir-opt-level=1

---
 compiler/rustc_session/src/session.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 580c9f2a34b17..b604bc23311b8 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -620,7 +620,7 @@ impl Session {
         self.opts
             .unstable_opts
             .mir_opt_level
-            .unwrap_or_else(|| if self.opts.optimize != OptLevel::No { 2 } else { 1 })
+            .unwrap_or_else(|| if self.opts.optimize != OptLevel::No { 2 } else { 0 })
     }
 
     /// Calculates the flavor of LTO to use for this compilation.