System Information
Operating system:Windows 10
Graphics card: Geforce GTX 1080 Ti

Blender Version
Broken:blender-2.80.0-git.4ef09cf937f2-windows64

Short description of error
Parenting of bones causes blender to crash

Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).
1.Create a mesh to animate.
2.Create multiple sets of bones.
3.Try to Parent them to the main 'bone' before attaching the entire rig to the mesh
4.After parenting the bones, press Tab to get out of edit mode into object mode, and watch blender crash.