From a1676741a8d664b1f3f850c0431f1418ce5aa99a Mon Sep 17 00:00:00 2001
From: Federico Poli <federpoli@gmail.com>
Date: Wed, 6 Mar 2024 09:56:31 +0100
Subject: [PATCH] Disable MIR optimization in tests

---
 prusti-tests/tests/compiletest.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/prusti-tests/tests/compiletest.rs b/prusti-tests/tests/compiletest.rs
index c1dafc5a37b..6c2ff38516d 100644
--- a/prusti-tests/tests/compiletest.rs
+++ b/prusti-tests/tests/compiletest.rs
@@ -83,7 +83,11 @@ fn run_prusti_tests(group_name: &str, filter: &Option<String>, rustc_flags: Opti
     }
 
     // Add compilation flags
-    config.target_rustcflags = Some(format!("--edition=2018 {}", rustc_flags.unwrap_or("")));
+    // mir-opt-level=0 disabled MIR optimizations (e.g., const propagation) that might hide bugs.
+    config.target_rustcflags = Some(format!(
+        "--edition=2018 -Z mir-opt-level=0 {}",
+        rustc_flags.unwrap_or("")
+    ));
 
     let path: PathBuf = ["tests", group_name, "ui"].iter().collect();
     if path.exists() {