sbt error: NoClassDefFoundError: org/fusesource/jansi/AnsiOutputStream

As a note to self, if you see this sbt error message with sbt 1.4.8, it’s a known issue:

java.lang.NoClassDefFoundError: org/fusesource/jansi/AnsiOutputStream

The short solution to the problem is to upgrade to sbt 1.4.9 or newer. The problem and solution are discussed in this Github sbt issue.