Correctly set --cap-lints when running regex tests

Author: GuillaumeGomez

build_system/src/config.rs

@@ -149,9 +149,11 @@ impl ConfigInfo {
                 .extend_from_slice(&["--sysroot".to_string(), sysroot_path.display().to_string()]);
         };
 
+        // This environment variable is useful in case we want to change options of rustc commands.
         if let Some(cg_rustflags) = env.get("CG_RUSTFLAGS") {
             rustflags.extend_from_slice(&split_args(&cg_rustflags));
         }
+
         if let Some(linker) = linker {
             rustflags.push(linker.to_string());
         }

build_system/src/test.rs

@@ -750,7 +750,8 @@ fn extended_regex_example_tests(env: &Env, args: &TestArg) -> Result<(), String>
     println!("[TEST] rust-lang/regex example shootout-regex-dna");
     let mut env = env.clone();
     // newer aho_corasick versions throw a deprecation warning
-    env.insert("CG_RUSTFLAGS".to_string(), "--cap-lints warn".to_string());
+    let rustflags = format!("{} --cap-lints warn", env.get("RUSTFLAGS").cloned().unwrap_or_default());
+    env.insert("RUSTFLAGS".to_string(), rustflags);
     // Make sure `[codegen mono items] start` doesn't poison the diff
     run_cargo_command(
         &[&"build", &"--example", &"shootout-regex-dna"],
@@ -798,7 +799,8 @@ fn extended_regex_tests(env: &Env, args: &TestArg) -> Result<(), String> {
     println!("[TEST] rust-lang/regex tests");
     let mut env = env.clone();
     // newer aho_corasick versions throw a deprecation warning
-    env.insert("CG_RUSTFLAGS".to_string(), "--cap-lints warn".to_string());
+    let rustflags = format!("{} --cap-lints warn", env.get("RUSTFLAGS").cloned().unwrap_or_default());
+    env.insert("RUSTFLAGS".to_string(), rustflags);
     run_cargo_command(
         &[
             &"test",