I have installed Blender 2.79b on Dell AMD laptop with Ubuntu 18.04. There is NO Alembic export available in the export menu. Then I installed same Blender on Macbook Pro with OSX and Alembic export is there?! I can't find anything about this issue anywhere on the net. Does anybody have a clue what's going on?
After having the same problem I figured out a solution.
I installed a different ppa and then went into Synaptic, uninstalled the stock Blender and installed the cutting edge build. The import and export options are there! Yay!
Here's the ppa homepage:
Pop!_os -- Ubuntu 18.04