Having unpinned Ruby2JS, I found that board/agenda no longer worked.
This turned out to be due to Ruby2JS generating a syntax error for events,js.rb.
This seems to have emerged in v4.0.0.
The symptom is a line of the form:
Events.broadcast(function(, ) {
which is a syntax error.
This is caused by the source line:
Events.broadcast json.reporter.merge(type: :reporter)
This error only seems to occur when eslevel: 5 is set.
The Gemfile for board/agenda has been reverted to Ruby2JS v3.6.1 and
the app now works.
Sebb