Upgrade path for CouchDB 1.x to 2.x on macOS?
As of now, Apache CouchDB 2.1 is available via Homebrew Cask.

Executing:

brew cask info apache-couchdb

lists the following output:

apache-couchdb: 2.1.1
https://couchdb.apache.org/
Not installed
From: https://github.com/caskroom/homebrew-cask/blob/master/Casks/apache-couchdb.rb
==&gt; Name
Apache CouchDB
==&gt; Artifacts
Apache CouchDB.app (App)