Upgrading to cfengine-3.4.x branch, and getting stuck cf-execd processes?

The behavior of -F flag has changed from 3.3.x to 3.4.x branch:

    Changed functionality:
    
    - cf-execd -F switch no longer implies 'run once'. New -O/--once
    option is added to achieve this behaviour. This makes cf-execd
    easier to run from systemd, launchd and other supervision
    systems.

So you need to update your crontab promises to add *-O* flag to *cf-execd -F*, to get the old (and correct for crontab) behavior:

    */5 * * * * root /var/cfengine/bin/cf-execd -FO