Display the sanitizer config in the regrtest header.

Lib/test/libregrtest/main.py

@@ -526,6 +526,26 @@ def display_header(self):
             print("== CPU count:", cpu_count)
         print("== encodings: locale=%s, FS=%s"
               % (locale.getencoding(), sys.getfilesystemencoding()))
+        asan = support.check_sanitizer(address=True)
+        msan = support.check_sanitizer(memory=True)
+        ubsan = support.check_sanitizer(ub=True)
+        # This makes it easier to remember what to set in your local
+        # environment when trying to reproduce a sanitizer failure.
+        if asan or msan or ubsan:
+            names = [n for n in (asan and "address",
+                                 msan and "memory",
+                                 ubsan and "undefined behavior")
+                     if n]
+            print(f"== sanitizers: {', '.join(names)}")
+            a_opts = os.environ.get("ASAN_OPTIONS")
+            if asan and a_opts is not None:
+                print(f"==  ASAN_OPTIONS={a_opts}")
+            m_opts = os.environ.get("ASAN_OPTIONS")
+            if msan and m_opts is not None:
+                print(f"==  MSAN_OPTIONS={m_opts}")
+            ub_opts = os.environ.get("UBSAN_OPTIONS")
+            if ubsan and ub_opts is not None:
+                print(f"==  UBSAN_OPTIONS={ub_opts}")
 
     def no_tests_run(self):
         return not any((self.good, self.bad, self.skipped, self.interrupted,

Lib/test/support/__init__.py

@@ -414,7 +414,7 @@ def check_sanitizer(*, address=False, memory=False, ub=False):
     )
     address_sanitizer = (
         '-fsanitize=address' in _cflags or
-        '--with-memory-sanitizer' in _config_args
+        '--with-address-sanitizer' in _config_args
     )
     ub_sanitizer = (
         '-fsanitize=undefined' in _cflags or