Godot Crash related to Area2D.set_enable_monitoring()

Preamble: The crash seems to be related to using Area2D.set_enable_monitoring() on an Area2D created in code via .new(), set up and added to an exxisting node in the scene.

ERROR: move: Condition ' !is_inside_scene() ' is true. returned: Vector2()
   At: scene/2d/physics_body_2d.cpp:758.
ERROR: move: Condition ' !is_inside_scene() ' is true. returned: Vector2()
   At: scene/2d/physics_body_2d.cpp:758.
ERROR: move: Condition ' !is_inside_scene() ' is true. returned: Vector2()
   At: scene/2d/physics_body_2d.cpp:758.

(many many repeats)

Program received signal SIGSEGV, Segmentation fault.
0x087b6b86 in Vector<Area2D::ShapePair>::size (this=0x9d7e954) at core/vector.h:95
95                              return *reinterpret_cast<int*>(((uint8_t*)(_ptr))+sizeof(SafeRefCount));

(gdb) backtrace
#0  0x087b6b86 in Vector<Area2D::ShapePair>::size (this=0x9d7e954) at core/vector.h:95
#1  0x087b7061 in VSet<Area2D::ShapePair>::_find (this=0x9d7e954, p_val=..., r_exact=@0xbfffea6b: false) at core/vset.h:48
#2  0x087b6609 in VSet<Area2D::ShapePair>::insert (this=0x9d7e954, p_val=...) at core/vset.h:103
#3  0x087b2f45 in Area2D::_body_inout (this=0x9d66e00, p_status=0, p_body=..., p_instance=534, p_body_shape=0, p_area_shape=0)
    at scene/2d/area_2d.cpp:162
#4  0x0874fbfd in MethodBind5<int, RID const&, int, int, int>::call (this=0x9aaf940, p_object=0x9d66e00, p_args=0xbfffef48, p_arg_count=5,
    r_error=...) at core/method_bind.inc:3017
#5  0x08b33ab0 in Object::call (this=0x9d66e00, p_method=..., p_args=0xbfffef48, p_argcount=5, r_error=...) at core/object.cpp:890
#6  0x089ba27d in Area2DSW::call_queries (this=0x9d66fa0) at servers/physics_2d/area_2d_sw.cpp:164
#7  0x089b1acf in Space2DSW::call_queries (this=0x9b50330) at servers/physics_2d/space_2d_sw.cpp:571
#8  0x089a88e3 in Physics2DServerSW::flush_queries (this=0x973cfb0) at servers/physics_2d/physics_2d_server_sw.cpp:1092
#9  0x0805bae0 in Main::iteration () at main/main.cpp:1272
#10 0x08051f77 in OS_X11::run (this=0xbffff190) at platform/x11/os_x11.cpp:1277
#11 0x0804df2b in main (argc=3, argv=0xbffff4f4) at platform/x11/godot_x11.cpp:41