bpo-36611: Disable serialno field of debug memory allocators (#12796)

Omit serialno field from debug hooks on Python memory allocators to
reduce the memory footprint by 5%.

Enable tracemalloc to get the traceback where a memory block has been
allocated when a fatal memory error is logged to decide where to put
a breakpoint.

Compile Python with PYMEM_DEBUG_SERIALNO defined to get back the
field.

1 files changed, 2 insertions, 2 deletions

diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 33c98ac..31dab6a 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -483,7 +483,7 @@ class PyMemDebugTests(unittest.TestCase):
                  r"        at tail\+1: 0xfd\n"
                  r"        at tail\+2: 0xfd\n"
                  r"        .*\n"
-                 r"    The block was made by call #[0-9]+ to debug malloc/realloc.\n"
+                 r"(    The block was made by call #[0-9]+ to debug malloc/realloc.\n)?"
                  r"    Data at p: cd cd cd .*\n"
                  r"\n"
                  r"Enable tracemalloc to get the memory block allocation traceback\n"
@@ -499,7 +499,7 @@ class PyMemDebugTests(unittest.TestCase):
                  r"    16 bytes originally requested\n"
                  r"    The [0-9] pad bytes at p-[0-9] are FORBIDDENBYTE, as expected.\n"
                  r"    The [0-9] pad bytes at tail={ptr} are FORBIDDENBYTE, as expected.\n"
-                 r"    The block was made by call #[0-9]+ to debug malloc/realloc.\n"
+                 r"(    The block was made by call #[0-9]+ to debug malloc/realloc.\n)?"
                  r"    Data at p: cd cd cd .*\n"
                  r"\n"
                  r"Enable tracemalloc to get the memory block allocation traceback\n"