System Information
Operating system: Win7 64
Graphics card: GeForce 980Ti

Blender Version
Broken: blender-2.80.0-git.26d5a3625ed-windows64 (official beta)

Short description of error
The scopes don't work in the image editor (graticules are there but no signal)
Error message displayed in the status bar (bottom) : Tool 'Select Box' not found for space 'IMAGE_EDITOR'

Exact steps for others to reproduce the error
Based on the default startup
Open an image in the image editor : no scopes :/