How to reproduce:
1. Open the attached project (that contains '2D Common' package)
2. Observe the Console window

Expected result: There are no Console errors caused by '2D Common' package.
Actual result: There is a compile error message "CS1061: 'SpriteRenderer' does not contain a definition for 'SetDeformableBuffer' <...>" that prevents from entering Play mode.

Reproducible with - 2018.2.0a2, 2018.2.16f1, 2018.3.0a1, 2018.3.0b10, 2019.1.0a1, 2019.1.0a8
Not reproducible with - 2018.2.0a1, 2019.1.0a9

Error thrown:
Packages\com.unity.2d.common\Runtime\InternalBridge\InternalEngineBridge.cs(15,28): error CS1061: 'SpriteRenderer' does not contain a definition for 'SetDeformableBuffer' and no accessible extension method 'SetDeformableBuffer' accepting a first argument of type 'SpriteRenderer' could be found (are you missing a using directive or an assembly reference?)

Fixed in 2019.1.0a9