With the upgrade to CirrusSearch/Elastica for ElasticSearch 7.10, a few Flow codepaths are now referencing invalid Elastica libraries. This hasn't blown up in production because apparently Flow search was not deployed (or was undeployed?), see T76823: Basic search on Flow board (tracking) and T62493: StructuredDiscussions posts are not indexed in builtin search among others.

Some options:

1. Remove the undeployed code
2. Adapt the undeployed code to the new version of Elastica
3. Rewrite the Phan stubs to pretend that the old Elastica libraries exist

I'm in favor of option 1, given the status of Flow.