Remove RTLD_GLOBAL flag from apps. (#2312)

* Remove RTLD_GLOBAL flag from apps.

* Set RTLD_GLOBAL in habitat-sim __init__.py.

* Change direct flag set by magnum import, which does the equivalent.

* Pre-commit pass.

examples/motion_viewer.py

@@ -2,15 +2,10 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
-import ctypes
 import random
-import sys
 import time
 from typing import Any, Callable, Dict, Optional, Tuple
 
-flags = sys.getdlopenflags()
-sys.setdlopenflags(flags | ctypes.RTLD_GLOBAL)
-
 import magnum as mn
 from magnum.platform.glfw import Application
 from viewer import HabitatSimInteractiveViewer, MouseMode, Timer

examples/viewer.py

@@ -2,18 +2,13 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
-import ctypes
 import math
 import os
 import string
-import sys
 import time
 from enum import Enum
 from typing import Any, Callable, Dict, List, Optional, Tuple
 
-flags = sys.getdlopenflags()
-sys.setdlopenflags(flags | ctypes.RTLD_GLOBAL)
-
 import magnum as mn
 import numpy as np
 from magnum import shaders, text

src_python/habitat_sim/__init__.py

@@ -6,6 +6,12 @@
 
 import builtins
 
+# Important platform-specific setup steps to do before using bindings.
+try:
+    import magnum
+except ImportError:
+    pass
+
 __version__ = "0.3.1"
 
 if not getattr(builtins, "__HSIM_SETUP__", False):