Participant Bodies after 01/2017 update

[nnamfoh]

I'm trying to use the new participantbodies feature from the update on an Join Extrusion, but it throws a weird error. 

Here is my code.

def buildBolt( parentComp, diameter, length, withHead = False):
    sketches = parentComp.sketches
    xZPlane = parentComp.xZConstructionPlane
    center = parentComp.originConstructionPoint.geometry
    extrudes = parentComp.features.extrudeFeatures
    bodies = []
    if withHead:
        sketch = sketches.add(xZPlane)
        sketch.sketchCurves.sketchCircles.addByCenterRadius(center, (diameter+.3)/2)
        prof = sketch.profiles[0]
        extInput = extrudes.createInput(prof, adsk.fusion.FeatureOperations.NewBodyFeatureOperation)
        distanceExtent = adsk.fusion.DistanceExtentDefinition.create(adsk.core.ValueInput.createByReal(.2))
        extInput.setOneSideExtent(distanceExtent, adsk.fusion.ExtentDirections.NegativeExtentDirection)
        extrude = extrudes.add(extInput)
        for body in extrude.bodies:
            Globals.ui.messageBox(str(body.classType()))
            bodies.append(bodies)
    try:
        bodySketch = sketches.add(xZPlane)
        bodySketch.sketchCurves.sketchCircles.addByCenterRadius(center, diameter/2)
        prof = bodySketch.profiles[0]
        extInput = extrudes.createInput(prof, adsk.fusion.FeatureOperations.JoinFeatureOperation)
        distanceExtent = adsk.fusion.DistanceExtentDefinition.create(adsk.core.ValueInput.createByReal(length))
        extInput.setOneSideExtent(distanceExtent, adsk.fusion.ExtentDirections.PositiveExtentDirection)
        extInput.participantBodies = bodies
        extrude = extrudes.add(extInput)
    except: 
        Globals.ui.messageBox('Failed:\n{}'.format(traceback.format_exc()))

The resulting error is thrown at "extInput.particpantBodies = bodies"

TypeError: in method 'extrudeFeatureInput__set_participantBodies', argument 2 of type 'std::vector<adsk::core::Ptr<adsk::fusion::BRepBody >?, std::allocator<adsk::core::Ptr< adsk::fusion::BRepBody > > > const &'

Since this feature is so new could this be a bug? I can work around it, but I would really like to know what I'm doing wrong.

[ekinsb]

Hopefully you found the error already but if not, look a little closer at the loop where you're adding the bodies to the array.  You have:

for body in extrude.bodies:
    bodies.append(bodies)

Notice what you're adding to the list.  it's the list "bodies" instead of the variable "body" which is the body you want.

Don't feel bad.  I don't know how many times I've made similar simple mistakes.