User migrations fail with missing roles

Problem/Motivation

The filter_format_permission process plugin hard codes the migration lookup name. This should be configurable, similar to #2640842: Make related file migration ID configurable in d6_cck_file.

Proposed resolution

Make the configuration configurable.

public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration = NULL) {
return new static(
$configuration,
$plugin_id,
$plugin_definition,
$migration,
$container->get('plugin.manager.migrate.process')->createInstance('migration', ['migration' => 'd6_filter_format'], $migration)
);
}

Remaining tasks

• code it.
• review it.
• update/add change record

User interface changes

n/a

API changes

n/a

Data model changes

Original report

I get the following error when trying to import users

InvalidArgumentException: Passed variable is not an array or object, using empty array instead in /var/www/docroot/core/modules/migrate/src/Plugin/migrate/process/Flatten.php:30
Stack trace:
#0 /var/www/docroot/core/modules/migrate/src/Plugin/migrate/process/Flatten.php(30): ArrayIterator->__construct(NULL)
#1 /var/www/docroot/core/modules/migrate/src/MigrateExecutable.php(395): Drupal\migrate\Plugin\migrate\process\Flatten->transform(NULL, Object(Drupal\migrate_tools\MigrateExecutable), Object(Drupal\migrate\Row), 'permissions')
#2 /var/www/docroot/core/modules/migrate/src/Plugin/migrate/process/Migration.php(139): Drupal\migrate\MigrateExecutable->processRow(Object(Drupal\migrate\Row), Array)
#3 /var/www/docroot/core/modules/migrate/src/MigrateExecutable.php(381): Drupal\migrate\Plugin\migrate\process\Migration->transform(Array, Object(Drupal\migrate_tools\MigrateExecutable), Object(Drupal\migrate\Row), 'roles')
#4 /var/www/docroot/core/modules/migrate/src/MigrateExecutable.php(218): Drupal\migrate\MigrateExecutable->processRow(Object(Drupal\migrate\Row))
#5 /usr/local/share/drush/includes/drush.inc(720): Drupal\migrate\MigrateExecutable->import()
#6 /usr/local/share/drush/includes/drush.inc(711): drush_call_user_func_array(Array, Array)
#7 /var/www/docroot/modules/contrib/migrate_tools/migrate_tools.drush.inc(280): drush_op(Array)
#8 [internal function]: _drush_migrate_tools_execute_migration(Object(Drupal\migrate\Plugin\Migration), 'awm_users', Array)
#9 /var/www/docroot/modules/contrib/migrate_tools/migrate_tools.drush.inc(246): array_walk(Array, '_drush_migrate_...', Array)
#10 /usr/local/share/drush/includes/command.inc(422): drush_migrate_tools_migrate_import('awm_users')
#11 /usr/local/share/drush/includes/command.inc(231): _drush_invoke_hooks(Array, Array)
#12 /usr/local/share/drush/includes/command.inc(199): drush_command('awm_users')
#13 /usr/local/share/drush/lib/Drush/Boot/BaseBoot.php(73): drush_dispatch(Array)
#14 /usr/local/share/drush/includes/preflight.inc(93): Drush\Boot\BaseBoot->bootstrap_and_dispatch()
#15 /usr/local/share/drush/drush.php(11): drush_main()
#16 {main}

I've generated this from the migrate-update --config-only drush command

langcode: en
status: true
dependencies: {  }
id: awm_users
migration_tags:
  - 'Drupal 7'
migration_group: migrate_drupal_7
label: 'User accounts'
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
    migration: awm_users_role
    source: roles
  user_picture:
    -
      plugin: default_value
      source: picture
      default_value: null
    -
      plugin: migration
      migration: upgrade_d7_file
destination:
  plugin: 'entity:user'
migration_dependencies:
  required:
    - awm_users_role
  optional:
    - upgrade_d7_file
    - upgrade_language
    - upgrade_default_language
    - upgrade_user_picture_field_instance
    - upgrade_user_picture_entity_display
    - upgrade_user_picture_entity_form_display
    - upgrade_d7_field_instance
    - upgrade_d7_user_role

Using Drupal 8.2.5. awm_users_role migrated ok.

Tbh I have no idea which of the 9 additional migration modules this would fall under. I'm trying to do a selective migration from drupal 7 to 8, so generating the migration templates through drush, and then running migrate-import.