Sadly the 0.22 ruby library has a new feature Container#schedule that does not work properly (scheduled code sometimes doesn't run) - it's very likely users will run into this if they use the feature.
I have fixed this properly for 0.23 and there's a small monkey patch to work around it on 0.22, see the description of https://issues.apache.org/ jira/browse/PROTON-1820
