how to use the slider of the shapekey value for moving the shapekey and the bone connected to it I'm trying to connect the shapekeys that comes from the manuel bastioni lab to the bones that come from rigify. Infact I’ve used two armatures to get the best from both these rigging systems and I have connected them into one only armature that I have called rig. 

I want that when I move the value of the shapekeys expressions, the bone should also move and both should deform the mesh. 

I’ve watched some tutorials where the authors move the bones and the mesh connected with the shapekey also move. But I don’t need this. 

I wanna move the slider of the value of the shapekey at the same time the bone that I have previously connected with the addon and the mesh should be deformed. 

In my case,I have created a driver,but it does not work correctly,because a cyclic dependency error.

So,what’s the solution here ? 

I’m trying to convert the set of shapekeys of the manuel bastioni lab to a set of (bones) poses.





Update : I configured the driver like this,but it does not work :





update 2 : After having tried to follow the kraken suggestion,I have solved half problem,but not everything. Infact now with the child of contraint I'm able to move the bone through the shapekey value,but when I add a pose on the poselib it sticks but I can't clear the transformations. Just need to fix this...check the video below to understand..

video to show that the clear transformations don't work
I forgot to mention.  the Cube in the file is the parent of the sphere.  If you move the cube, the sphere follows.  If you change the constraint modifier of the sphere to .5 it will follow half as much.      This method can be applied to your bones so that one bone controls another bone which controls the face.