"fast_gettext" error in Puppet Enterprise when upgrading from Puppet agent 5.3.3 (PE 2017.3.2) and earlier to 5.3.4 (PE 2017.3.4) and later

I get a fast_gettext error when upgrading Puppet agent from 5.3.3 (PE 2017.3.2) to 5.3.4 (PE 2017.3.4). How do I resolve it?

Error messages and logs

During upgrade, the fast_gettext 1.1.0 localization gem is removed and replaced with fast_gettext 1.1.2. When the agent runs, string translation fails because a file in the older version of the gem no longer exists, and you get the following error:

Error: Could not convert change ensure to string: No such file or directory @ rb_sysopen - /opt/puppetlabs/puppet/lib/ruby/gems/2.4.0/gems/fast_gettext-1.1.0/lib/fast_gettext/vendor/empty.mo Error: No such file or directory @ rb_sysopen - /opt/puppetlabs/puppet/lib/ruby/gems/2.4.0/gems/fast_gettext-1.1.0/lib/fast_gettext/vendor/empty.mo

Version and installation information

PE version: 2017.3.2 and earlier upgrading to 2017.3.4 and later

Solution

This error can safely be ignored. The error occurs only during upgrade and will not occur during subsequent runs.