M src/platform/python/mgba/core.py → src/platform/python/mgba/core.py

@@ -105,8 +105,13 @@ self._callbacks = CoreCallbacks()
         self._core.addCoreCallbacks(self._core, self._callbacks.context)
         self.config = Config(ffi.addressof(native.config))
 
+    def __del__(self):
+        self._wasReset = False
+
     @cached_property
     def graphicsCache(self):
+        if not self._wasReset:
+            raise RuntimeError("Core must be reset first")
         return tile.CacheSet(self)
 
     @cached_property

M src/platform/python/mgba/gb.py → src/platform/python/mgba/gb.py

@@ -32,8 +32,9 @@ lib.GBVideoCacheInit(cache)
         lib.GBVideoCacheAssociate(cache, ffi.addressof(self._native.video))
 
     def _deinitCache(self, cache):
-        self._native.video.renderer.cache = ffi.NULL
         lib.mCacheSetDeinit(cache)
+        if self._wasReset:
+            self._native.video.renderer.cache = ffi.NULL
 
     def reset(self):
         super(GB, self).reset()

M src/platform/python/mgba/gba.py → src/platform/python/mgba/gba.py

@@ -40,8 +40,9 @@ lib.GBAVideoCacheInit(cache)
         lib.GBAVideoCacheAssociate(cache, ffi.addressof(self._native.video))
 
     def _deinitCache(self, cache):
-        self._native.video.renderer.cache = ffi.NULL
         lib.mCacheSetDeinit(cache)
+        if self._wasReset:
+            self._native.video.renderer.cache = ffi.NULL
 
     def reset(self):
         super(GBA, self).reset()