dependency issue: Failed to resolve eyp-dovecot (< 0.2.0, >= 0.1.3) <(no source specified)>

[juju4]

While trying role

$ librarian-puppet install --verbose
[Librarian] Ruby Version: 2.3.1
[Librarian] Ruby Platform: x86_64-linux-gnu
[Librarian] Rubygems Version: 2.5.2.1
[Librarian] Librarian Version: 0.6.3
[Librarian] Librarian Adapter: puppet
[Librarian] Librarian Adapter Version: 2.2.1
[Librarian] Project: /media/user/26fcf073-3d3f-450e-bd49-f3b505a46ab5/tmp/Lab1/git-roles/puppet-meta-harden-linux
[Librarian] Specfile: Puppetfile
[Librarian] Lockfile: Puppetfile.lock
[Librarian] Git: /usr/bin/git
[Librarian] Git Version: 2.7.4
[Librarian] Git Environment Variables:
[Librarian]   (empty)
[Librarian] Pre-Cached Sources:
[Librarian]   [:forge, "https://forgeapi.puppetlabs.com", {}]
[Librarian] Post-Cached Sources:
[Librarian]   [:forge, "https://forgeapi.puppetlabs.com", {}]
[Librarian] Analyzing spec and lock:
[Librarian]   Removed:
[Librarian]   ExplicitRemoved:
[Librarian]   Added:
[Librarian]     eyp-postfix
[Librarian]   NonMatchingAdded:
[Librarian]     eyp-postfix
[Librarian]   Changed:
[Librarian]   DeepKeep:
[Librarian]     bryana-osquery
[Librarian]     eyp-epel
[Librarian]     geoffwilliams-auditd
[Librarian]     hardening-hardening_stdlib
[Librarian]     hardening-os_hardening
[Librarian]     hardening-ssh_hardening
[Librarian]     itmanagerro-rkhunter
[Librarian]     justinjl-smarthost
[Librarian]     puppet-fail2ban
[Librarian]     puppet-rsyslog
[Librarian]     puppetlabs-accounts
[Librarian]     puppetlabs-apt
[Librarian]     puppetlabs-concat
[Librarian]     puppetlabs-firewall
[Librarian]     puppetlabs-ntp
[Librarian]     puppetlabs-stdlib
[Librarian]   ShallowStrip:
[Librarian] Resolving eyp-postfix (>= 0) <https://forgeapi.puppetlabs.com>
[Librarian]   Checking manifests
[Librarian]   Module eyp-postfix found versions: 0.2.32, 0.2.29, 0.2.25
[Librarian]     Checking eyp-postfix/0.2.32 <https://forgeapi.puppetlabs.com>
[Librarian]       Resolved eyp-postfix (>= 0) <https://forgeapi.puppetlabs.com> at eyp-postfix/0.2.32 <https://forgeapi.puppetlabs.com>
[Librarian]   Resolved eyp-postfix (>= 0) <https://forgeapi.puppetlabs.com>
[Librarian] Resolving eyp-dovecot (< 0.2.0, >= 0.1.3) <(no source specified)>
[Librarian]   Checking manifests
[Librarian]   Module eyp-dovecot found versions: 0.1.12, 0.1.10, 0.1.9, 0.1.8, 0.1.3, 0.1.2, 0.1.0
[Librarian]     Checking eyp-dovecot/0.1.12 <https://forgeapi.puppetlabs.com>
[Librarian]       Cycle with eyp-dovecot/0.1.12 <https://forgeapi.puppetlabs.com>
[Librarian]       Backtracking from eyp-dovecot/0.1.12 <https://forgeapi.puppetlabs.com>
[Librarian]     Checking eyp-dovecot/0.1.10 <https://forgeapi.puppetlabs.com>
[Librarian]       Cycle with eyp-dovecot/0.1.10 <https://forgeapi.puppetlabs.com>
[Librarian]       Backtracking from eyp-dovecot/0.1.10 <https://forgeapi.puppetlabs.com>
[Librarian]     Checking eyp-dovecot/0.1.9 <https://forgeapi.puppetlabs.com>
[Librarian]       Cycle with eyp-dovecot/0.1.9 <https://forgeapi.puppetlabs.com>
[Librarian]       Backtracking from eyp-dovecot/0.1.9 <https://forgeapi.puppetlabs.com>
[Librarian]     Checking eyp-dovecot/0.1.8 <https://forgeapi.puppetlabs.com>
[Librarian]       Cycle with eyp-dovecot/0.1.8 <https://forgeapi.puppetlabs.com>
[Librarian]       Backtracking from eyp-dovecot/0.1.8 <https://forgeapi.puppetlabs.com>
[Librarian]     Checking eyp-dovecot/0.1.3 <https://forgeapi.puppetlabs.com>
[Librarian]       Cycle with eyp-dovecot/0.1.3 <https://forgeapi.puppetlabs.com>
[Librarian]       Backtracking from eyp-dovecot/0.1.3 <https://forgeapi.puppetlabs.com>
[Librarian]     Checking eyp-dovecot/0.1.2 <https://forgeapi.puppetlabs.com>
[Librarian]       Conflict between eyp-dovecot/0.1.2 <https://forgeapi.puppetlabs.com> and eyp-dovecot (< 0.2.0, >= 0.1.3) <(no source specified)>
[Librarian]       Backtracking from eyp-dovecot/0.1.2 <https://forgeapi.puppetlabs.com>
[Librarian]     Checking eyp-dovecot/0.1.0 <https://forgeapi.puppetlabs.com>
[Librarian]       Conflict between eyp-dovecot/0.1.0 <https://forgeapi.puppetlabs.com> and eyp-dovecot (< 0.2.0, >= 0.1.3) <(no source specified)>
[Librarian]       Backtracking from eyp-dovecot/0.1.0 <https://forgeapi.puppetlabs.com>
[Librarian]   Failed to resolve eyp-dovecot (< 0.2.0, >= 0.1.3) <(no source specified)>
Could not resolve the dependencies.

or

https://travis-ci.org/juju4/puppet-meta-harden-linux/jobs/420576055#L2312
https://travis-ci.org/juju4/puppet-meta-harden-linux/jobs/420576059#L2845

there is a circular dependency between dovecot (latest 0.1.12) and postfix (latest 0.2.32)
It's not clear why it is backtracking.

Any idea?

Thanks