Index: libcfa/src/concurrency/iocall.cfa
===================================================================
--- libcfa/src/concurrency/iocall.cfa	(revision 0aa20e318f1669fc4920a51333207f5c43329e58)
+++ libcfa/src/concurrency/iocall.cfa	(revision 2ecbd7bd42669e3d5c187c5bee962619b21edabe)
@@ -346,4 +346,6 @@
 }
 
+// Forward declare in case it is not supported
+struct statx;
 int cfa_statx(int dirfd, const char *pathname, int flags, unsigned int mask, struct statx *statxbuf) {
 	#if !defined(HAVE_LINUX_IO_URING_H) || !defined(IORING_OP_STATX)
Index: libcfa/src/concurrency/kernel.cfa
===================================================================
--- libcfa/src/concurrency/kernel.cfa	(revision 0aa20e318f1669fc4920a51333207f5c43329e58)
+++ libcfa/src/concurrency/kernel.cfa	(revision 2ecbd7bd42669e3d5c187c5bee962619b21edabe)
@@ -735,5 +735,4 @@
 void __unpark(  struct __processor_id_t * id, $thread * thrd __cfaabi_dbg_ctx_param2 ) {
 	// record activity
-	__cfaabi_dbg_debug_do( char * old_caller = thrd->unpark_caller; )
 	__cfaabi_dbg_record_thrd( *thrd, false, caller );
 
Index: libcfa/src/concurrency/kernel_private.hfa
===================================================================
--- libcfa/src/concurrency/kernel_private.hfa	(revision 0aa20e318f1669fc4920a51333207f5c43329e58)
+++ libcfa/src/concurrency/kernel_private.hfa	(revision 2ecbd7bd42669e3d5c187c5bee962619b21edabe)
@@ -36,5 +36,9 @@
 }
 
-void __schedule_thread( struct __processor_id_t *, $thread * ) __attribute__((nonnull (2)));
+void __schedule_thread( struct __processor_id_t *, $thread * )
+#if defined(NDEBUG) || (!defined(__CFA_DEBUG__) && !defined(__CFA_VERIFY__))
+	__attribute__((nonnull (2)))
+#endif
+;
 
 //Block current thread and release/wake-up the following resources