Just wondering is the x-asix mirror feature added back yet for rigging in 2.8? Hoping not to have to redo my rig work on Right side 
I’ve noticed i can use symmetrize or something in drop down to copy across my bone setup but when doing constraints, the constraining setup isnt being mirrored as was in 2.79.
Cheers!
Jono
X-axis option is working in edit mode only.
Constraining should be mirrored, too by symmetrize. Maybe you forgot a target of constraint that did not have an L suffix.
If you are talking about python constraints, it is probably normal. Python API was not released, yet.
Ok im thinking i must be blind…could you please tell me where the x-axis option has gone? I’ve used it dozens of times in 2.79 but for the life of me cant find it in 2.8.
Symmetrize is also only an option in edit mode not pose mode where you create constraints. I’m just wondering if it hasnt been re-added yet? Or maybe im just blind lol
Usually in 2.8 the interactive options like x-axis would be along the top bar. But im not seeing it.
X-axis option is the only thing present under Armature Options popover at right tip of Topbar.
I suppose that they are forced to use a panel container to be able to also display it into Tools tab of Properties Editor.
Symmetrize is in fourth section of Armature menu with Autoname operators.
It is true that is only available in edit mode. But you can switch from one mode to another at any time.
You can set a constraint in Pose Mode and, after that, go into edit mode to use Symmetrize.
oh! thank you!! i got a big screen…hahaha waaaay over on the right lol. Thanks!
I was struggling with it for hours, even after reading this whole thread, until I realised how “hidden” this option was!! insane!! 
If after reading this thread you still have problems in finding the X axis mirror while on Edit Mode in Rigging, here is an image to help you:
Thank you for the posted image, as I wasn’t settled yet on where it is located. I will try this out.
Thank you!
Thankyou so much! I spent a whole half hour looking for this stupid option, going “surely they haven’t gotten rid of it???”
Now is here
… It took me 4 hours to find this.
Not for me 
I just wan’t to apply a rig, this stuff is frustrating enough as it is. Ah well, that’s what you get for alpha software.
It is there in the blender-2.80.0-git.40412499433e-windows64 version but not in the blender-2.80-05f1451d7248-win64 version.
Sjeex.
It’s here in the latest build. 
you saved my day thanks a lot
Thank you I was lost again!
Thank you so much!! You saved my day! 
It’s here in the latest build (July I think). I found this. But, you should change to Edit Mode first.
I drew the red circle
I LOVE YOU!!!
No, for real though, thank you so much for saving me from “one of those nights”
