gh-137007: Track executor before any possible deallocations

Misc/NEWS.d/next/Core_and_Builtins/2025-07-22-16-20-06.gh-issue-137007.1oPvvK.rst

@@ -0,0 +1 @@
+Fix a bug during JIT compilation failure which caused garbage collection debug assertions to fail.

Python/optimizer.c

@@ -1205,6 +1205,10 @@ make_executor_from_uops(_PyUOpInstruction *buffer, int length, const _PyBloomFil
     assert(next_exit == -1);
     assert(dest == executor->trace);
     assert(dest->opcode == _START_EXECUTOR);
+    // Note: we MUST track it here before any Py_DECREF(executor) or
+    // linking of executor. Otherwise, the GC tries to untrack a
+    // still untracked object during dealloc.
+    _PyObject_GC_TRACK(executor);
     _Py_ExecutorInit(executor, dependencies);
 #ifdef Py_DEBUG
     char *python_lltrace = Py_GETENV("PYTHON_LLTRACE");
@@ -1234,7 +1238,6 @@ make_executor_from_uops(_PyUOpInstruction *buffer, int length, const _PyBloomFil
         return NULL;
     }
 #endif
-    _PyObject_GC_TRACK(executor);
     return executor;
 }