After installing the latest daily build, I no longer find the addon manager. Below is a screenshot of my Tools menu.

Thanks for any illuminating comments!
Zoltán
OS: Ubuntu 18.04.2 LTS (X-Cinnamon/cinnamon)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.
Build type: Release
Python version: 3.6.8
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)