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:
I'm in favor of option 1, given the status of Flow.
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4