randomsleep uses slapos.recipe.build, which does not support shared
feature.

It seems we can rewrite it using slapos.recipe.cmmi or other options ?

The work on cmmi share makes me believe slapos.recipe.build is not
necessary and we can use slapos.recipe.cmmi everywhere, but I don't know
the reason that leaded us to have two duplicates recipes in the first
place.