Forum OpenACS Q&A: Selva themes not installing in oacs-5-2

I just created a new instance of 5-2 from CVS, and upon installation, I get:

Installing Selva Theme 0.5d

Installed Selva Theme, version 0.5d.

Package enabled.

Theme-selva not installed.

Error:

    site node not found at url ""

    site node not found at url "" while executing "error "site node not found at url \"$url\""" (procedure "get_from_url" line 33) invoked from within "get_from_url -url $url" (procedure "get" line 12) invoked from within "get -url $url" (procedure "site_node::get_node_id" line 3) invoked from within "site_node::get_node_id -url "/"" (procedure "apm_package_install" line 152) invoked from within "apm_package_install -load_data_model -enable -callback $callback $spec_file"

Searching the site discovered this .LRN discussion:
https://openacs.org/forums/message-view?message_id=306063

It seems that some new .LRN needful has been added to 5-2, and judging from the discussion it is not quite set.  Am I misunderstanding something?  I ask principally referring to  https://openacs.org/projects/openacs/5.2/milestones  and the listed prohibition of introducing new features at this point in the 5.2 release.