Problems with upgrade

Problem:
Running foreman-installer after rpm upgrades results in failure

Expected outcome:
foreman-installer successful completion.

Foreman and Proxy versions:
katello 3.19 /foreman 2.3

Foreman and Proxy plugin versions:

Distribution and version:
Centos 7

Other relevant data:

foreman-installer
2021-02-19 19:44:30 [NOTICE] [pre_migrations] Executing hooks in group pre_migrations
2021-02-19 19:44:30 [NOTICE] [pre_migrations] All hooks in group pre_migrations finished
2021-02-19 19:44:30 [NOTICE] [boot] Executing hooks in group boot
2021-02-19 19:44:30 [NOTICE] [boot] All hooks in group boot finished
2021-02-19 19:44:30 [NOTICE] [init] Executing hooks in group init
2021-02-19 19:44:30 [NOTICE] [init] All hooks in group init finished
2021-02-19 19:44:30 [NOTICE] [root] Loading default values from puppet modules...
2021-02-19 19:44:37 [NOTICE] [root] ... finished
2021-02-19 19:44:37 [NOTICE] [pre_values] Executing hooks in group pre_values
2021-02-19 19:44:37 [NOTICE] [pre_values] All hooks in group pre_values finished
2021-02-19 19:44:41 [NOTICE] [pre_validations] Executing hooks in group pre_validations
2021-02-19 19:44:42 [NOTICE] [pre_validations] All hooks in group pre_validations finished
2021-02-19 19:44:42 [NOTICE] [root] Running validation checks
2021-02-19 19:44:42 [ERROR ] [root] Parameter foreman-plugin-default-hostgroup-hostgroups invalid: Elements of the array are invalid: Hash value elements are invalid: nil is not a valid hash
Error during configuration, exiting

That’s odd, maybe one that we missed. You can use --reset-foreman-plugin-default-hostgroup-hostgroups as an argument. That should reset it to the default value.

Before your reply I started a run with --no-enable-foreman-plugin-default-hostgroup
The upgrade failed because of pulp running.
I re-ran the upgrade with
–reset-foreman-plugin-default-hostgroup-hostgroups and it seems to have worked.

if I try running foreman-installer --enable-foreman-plugin-default-hostgroup
I get the error message even after --reset-foreman-plugin-default-hostgroup-hostgroups

Looking at the code, you may have hit a bug in our parser: Bug #31565: Validation of array's as static parameters on a class is incorrectly handled - Kafo - Foreman

I think the workaround is to modify your answers file manually. If you already have the RPM package installed, you don’t really need to though. The installer can’t remove the plugin so what --no-enable-foreman-plugin-default-hostgroup technically does is roughly “stop making sure the plugin is installed”.

How would I modify the answers file?