[[!comment format=mdwn username="http://joeyh.name/" subject="comment 1" date="2016-03-30T19:30:50Z" content=""" Well, I don't see a way around needing to release a version of propellor that fixes this bug before I can release a version of propellor that depends on the fix (by adding a new dependency on concurrent-output). So, I'll go that route. Users will need to upgrade all deployed hosts to propellor 2.17.2 first, before 3.0.0. If a user neglects to do so, and tries to update a host using propellor --spin, it will fail. The user can then either 1. Wait for the cron job to run, if they set it up, which will install the deps. 2. Manually log into the host and fix the deps by eg, cabal install concurrent-output as root. """]]