undefined method `[]' for nil:NilClass when handling SemanticPuppet::Dependency::UnsatisfiableGraph

Installed Software

1. rpm -qa |grep -E '(puppet|pdk)'
   puppet7-release-7.0.0-2.el7.noarch
   puppet-agent-7.8.0-1.el7.x86_64
   pdk-2.1.1.0-1.el7.x86_64

Steps to reproduce

I am trying to deploy a custom puppet module and I went through:

rake build:pdk

then:

puppet module install ./path/to/OUR_MODULE_NAME-3.0.0.tar.gz --debug

Desired Behavior:

Our module with all dependencies be installed

Actual Behavior:

Code exits non-zero trying to call ..constraints[*nil*].first[1]

It seems like the error is caused because of a logical issue at:

https://github.com/puppetlabs/puppet/blob/main/lib/puppet/module_tool/applications/installer.rb#L141

With some janky

{{ rescue SemanticPuppet::Dependency::UnsatisfiableGraph => e}}
  unsatisfied = nil
  pp 'e'
  pp e
  pp 'e.respond_to?(:unsatisfied)'
  pp e.respond_to?(:unsatisfied)
  pp 'e.respond_to?(:unsatisfied)'
  pp e.respond_to?(:unsatisfied)

The output below shows that `e` does respond to :unsatisfied, but e.unsatisfied is nil, so when it's called on L167 it fails

$ puppet module install ./pkg/OUR_MODULE_NAME-3.0.0.tar.gz --debug
Debug: Runtime environment: puppet_version=7.8.0, ruby_version=2.7.3, run_mode=user, default_encoding=UTF-8
Notice: Preparing to install into /home/vagrant/.puppetlabs/etc/code/modules ...
Debug: Could not find library 'archive/tar/minitar' required to enable feature 'minitar'
Debug: Executing: 'gzip -dc /REDACTED/pkg/OUR_MODULE_NAME-3.0.0.tar.gz | tar xof -'
Debug: Executing: 'find . -type d -exec chmod 755 {} +'
Debug: Executing: 'find . -type f -exec chmod u+rw,g+r,a-st {} +'
Debug: Executing: 'chown -R 1000:1000 .'
Debug: Unpacked local tarball to /home/vagrant/.puppetlabs/opt/puppet/cache/OUR_MODULE_NAME/cache/local-tarball20210721-26316-1jpeh2d
Notice: Downloading from https://forgeapi.puppet.com ...
Debug: Could not find library 'pe_license' required to enable feature 'pe_license'
Debug: Creating new connection for https://forgeapi.puppet.com:443
Debug: Starting connection for https://forgeapi.puppet.com:443
Debug: Using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384
Debug: HTTP GET https://forgeapi.puppet.com/v3/releases?module=cds-puppet&sort_by=version&exclude_fields=readme%2Cchangelog%2Clicense%2Curi%2Cmodule%2Ctags%2Csupported%2Cfile_size%2Cdownloads%2Ccreated_at%2Cupdated_at%2Cdeleted_at returned 200 OK
Debug: Caching connection for https://forgeapi.puppet.com:443
{{Debug: Using cached connection for [https://forgeapi.puppet.com:443

https://forgeapi.puppet.com/]}}<SOME OUTPUT OMITTED>

Debug: Caching connection for https://forgeapi.puppet.com:443
Debug: Using cached connection for https://forgeapi.puppet.com:443
Debug: HTTP GET https://forgeapi.puppet.com/v3/releases?module=thias-postfix&sort_by=version&exclude_fields=readme%2Cchangelog%2Clicense%2Curi%2Cmodule%2Ctags%2Csupported%2Cfile_size%2Cdownloads%2Ccreated_at%2Cupdated_at%2Cdeleted_at returned 200 OK
Debug: Caching connection for https://forgeapi.puppet.com:443
Info: Resolving dependencies ...

"e"
#<SemanticPuppet::Dependency::UnsatisfiableGraph: Could not find satisfying releases for OUR_MODULE_NAME>
"e.unsatisfied"
nil
"e.respond_to?(:unsatisfied)"
true

Error: undefined method `[]' for nil:NilClass
Error: Try 'puppet help module install' for usage

Bonus Info

• I am only seeing this now because I have finally been able to schedule time on upgrading from puppet 5, and am going straight to 7.
• rake works:
  • check
  • rubocop
  • lint
  • metadata_lint
  • validate