Use a Mutex to make sure only one test compiles artifacts in a given …

…directory at any time

Cargo.toml

@@ -142,6 +142,7 @@ build-data = "0.1.3"
 bincode = "1.3.3"
 hex = "0.4.2"
 const_format = "0.2.30"
+lazy_static = "1.4"
 num-bigint = "0.4"
 num-traits = "0.2"
 similar-asserts = "1.5.0"

acvm-repo/bn254_blackbox_solver/Cargo.toml

@@ -19,10 +19,10 @@ workspace = true
 acir.workspace = true
 acvm_blackbox_solver.workspace = true
 hex.workspace = true
-lazy_static = "1.4"
+lazy_static.workspace = true
 
 ark-bn254.workspace = true
-grumpkin.workspace = true 
+grumpkin.workspace = true
 ark-ec.workspace = true
 ark-ff.workspace = true
 num-bigint.workspace = true

tooling/nargo_cli/Cargo.toml

@@ -88,6 +88,7 @@ sha3.workspace = true
 iai = "0.1.1"
 test-binary = "3.0.2"
 test-case.workspace = true
+lazy_static.workspace = true
 light-poseidon = "0.2.0"
 
 

tooling/nargo_cli/build.rs

@@ -95,7 +95,12 @@ struct MatrixConfig {
 
 impl Default for MatrixConfig {
     fn default() -> Self {
-        Self { vary_brillig: false, vary_inliner: true }
+        Self {
+            // Only used with execution, and only on selected tests.
+            vary_brillig: false,
+            // Only seems to have an effect on the `execute_success` cases.
+            vary_inliner: false,
+        }
     }
 }
 
@@ -111,16 +116,25 @@ fn generate_test_cases(
     test_content: &str,
     matrix_config: &MatrixConfig,
 ) {
+    let mutex_name = format! {"TEST_MUTEX_{}", test_name.to_uppercase()};
     let brillig_cases = if matrix_config.vary_brillig { "[false, true]" } else { "[false]" };
     let inliner_cases = if matrix_config.vary_inliner { "[i64::MIN, 0, i64::MAX]" } else { "[0]" };
     write!(
         test_file,
         r#"
+lazy_static::lazy_static! {{
+    /// Prevent concurrent tests in the matrix from overwriting the compilation artifacts in {test_dir}
+    static ref {mutex_name}: std::sync::Mutex<()> = std::sync::Mutex::new(());
+}}
+
 #[test_case::test_matrix(
     {brillig_cases}, 
     {inliner_cases}
 )]
 fn test_{test_name}(force_brillig: bool, inliner_aggressiveness: i64) {{
+    // Ignore poisoning errors if some of the matrix cases failed.
+    let _guard = {mutex_name}.lock().unwrap_or_else(|e| e.into_inner()); 
+
     let test_program_dir = PathBuf::from("{test_dir}");
 
     let mut nargo = Command::cargo_bin("nargo").unwrap();