Why does d7_user_role need a db connection configured when migration group already defines it

Question

I've just done a super basic user_role import and I'm trying to do a user import. Both are in the same migration group and the migration group has a souce key to specify which database listed in settings.php to use.

I can migrate and roll back the user_role import fine, but as soon as I try to import the users, I get "Migration mysite_user did not meet the requirements. No database connection configured for source plugin d7_user_role"

migrate_plus.migration_group.basic_migration.yml

uuid: 512c4248-7f60-4b08-9cc2-8d804657262c  
langcode: en  
status: true  
dependencies: {  }  
id: basic_migration  
label: basic_migration  
description: 'basic migrations'  
source_type: 'Drupal 7'  
module: null  
shared_configuration:  
  source:  
    key: legacy  

migrate_plus.migration.mysite_role.yml

uuid: 6e288181-f2fd-4e22-885e-02282cc4d222  
langcode: en  
status: true  
dependencies: {  }  
id: mysite_role  
class: null  
field_plugin_method: null  
cck_plugin_method: null  
migration_tags:  
  - 'Drupal 7'  
  - Configuration  
migration_group: basic_migration  
label: 'Mysite Role'  
source:  
  plugin: d7_user_role  
process:  
  id:  
    -  
      plugin: machine_name  
      source: name  
    -  
      plugin: user_update_8002  
  label: name  
  permissions:  
    -  
      plugin: static_map  
      source: permissions  
      bypass: true  
      map:  
        'use PHP for block visibility': 'use PHP for settings'  
        'administer site-wide contact form': 'administer contact forms'  
        'post comments without approval': 'skip comment approval'  
        'edit own blog entries': 'edit own blog content'  
        'edit any blog entry': 'edit any blog content'  
        'delete own blog entries': 'delete own blog content'  
        'delete any blog entry': 'delete any blog content'  
        'create forum topics': 'create forum content'  
        'delete any forum topic': 'delete any forum content'  
        'delete own forum topics': 'delete own forum content'  
        'edit any forum topic': 'edit any forum content'  
        'edit own forum topics': 'edit own forum content'  
    -  
      plugin: flatten  
  weight: weight  
destination:  
  plugin: 'entity:user_role'  
migration_dependencies: null  

migrate_plus.migration.mysite_user.yml

uuid: bd0ef271-9c8f-40d7-9b65-8147e4cdda47  
langcode: en  
status: true  
dependencies: {  }  
id: mysite_user  
class: Drupal\user\Plugin\migrate\User  
field_plugin_method: null  
cck_plugin_method: null  
migration_tags:  
  - 'Drupal 7'  
  - Content  
migration_group: basic_migration  
label: 'Mysite User'  
source:  
  plugin: d7_user  
process:  
  uid: uid  
  name: name  
  pass: pass  
  mail: mail  
  created: created  
  access: access  
  login: login  
  status: status  
  timezone: timezone  
  langcode:  
    plugin: user_langcode  
    source: language  
    fallback_to_site_default: false  
  preferred_langcode:  
    plugin: user_langcode  
    source: language  
    fallback_to_site_default: true  
  preferred_admin_langcode:  
    plugin: user_langcode  
    source: language  
    fallback_to_site_default: true  
  init: init  
  roles:  
    plugin: migration_lookup  
    migration: d7_user_role  
    source: roles  
  user_picture:  
    -  
      plugin: default_value  
      source: picture  
      default_value: null  
    -  
      plugin: migration_lookup  
      migration: d7_file  
destination:  
  plugin: 'entity:user'  
migration_dependencies:  
  required:  
    - d7_user_role  
    - mysite_role  
  optional:  
    - d7_field_instance  
    - d7_file  
    - language  
    - default_language  
    - user_picture_field_instance  
    - user_picture_entity_display  
    - user_picture_entity_form_display  

Any pointers where to start looking would be much appreciated.

Answer 1

The section of migrate_plus.migration.mysite_user.yml that reads this:

roles:
plugin: migration_lookup
migration: d7_user_role
source: roles

has to be edited by switching "d7_user_role" for the id of your user role migration, which in your case is "mysite_role"

roles:
plugin: migration_lookup
migration: mysite_role
source: roles