Repro:
1) Create a new project pointing to SRP master.
2) Create a HDRP Asset.
3) In Project Settings / Graphics, set the Scriptable Render Pipeline to this newly create HDRP asset.
4) In the scene, create a new terrain.
5) Get close enough to the terrain, and it will flicker black & pink and an error will be generated.

Error:
Shader error in 'HDRP/TerrainLit': redefinition of '_Control0_TexelSize' at /GitHub/ScriptableRenderPipeline0/com.unity.render-pipelines.high-definition/Runtime/Material/TerrainLit/TerrainLit_Splatmap.hlsl(4) (on d3d11)

Bonus info:
If you get far enough away from the terrain it will look fine, meaning the basemap shader is fine.

Reproduced with 2020.1.0a2 (4a00acff388a) Sun, 18 Aug 2019 22:49:45 GMT, SRP master at Aug-21-2019 (78e2822441)