gcc -pthread -c -Wno-unused-result -Wsign-compare -DDYNAMIC_ANNOTATIONS_ENABLED=1 -g -Og -Wall    -std=c99 -Wextra -Wno-unused-result -Wno-unused-parameter -Wno-missing-field-initializers -Werror=implicit-function-declaration  -I./Include/internal  -I. -I./Include    -DPy_BUILD_CORE -o Objects/memoryobject.o Objects/memoryobject.c
Objects/memoryobject.c:3112:21: warning: cast between incompatible function types from 'PyObject * (*)(PyMemoryViewObject *, PyObject *, PyObject *)' {aka 'struct _object * (*)(struct <anonymous> *, struct _object *, struct _object *)'} to 'PyObject * (*)(PyObject *, PyObject *)' {aka 'struct _object * (*)(struct _object *, struct _object *)'} [-Wcast-function-type]
     {"tobytes",     (PyCFunction)memory_tobytes, METH_VARARGS|METH_KEYWORDS, memory_tobytes_doc},


I am preparing a small PR for this issue.