gistfile1.txt

static int camera_isinuse(lua_State *L) {
    LuaSkin *skin = [LuaSkin sharedWithState:L];
    [skin checkArgs:LS_TUSERDATA, USERDATA_TAG, LS_TBREAK];

    HSCamera *camera = [skin toNSObjectAtIndex:1];

// This was the original code here, crashed every time
//    lua_pushboolean(skin.L, camera.isInUse);
//    return 1;

// This is the new code here, and even this crashes without NSLog()
    NSLog(@"Camera: %@", camera);
    NSNumber *isInUse = [NSNumber numberWithBool:camera.isInUse];
    [skin pushNSObject:isInUse];
    return 1;
}