migrate:import loops over each migration, hits EOM before it finishes

[damienmckenna]

Describe the bug
With Drush 10.6.x running "migrate:import" on an upgrade from a D7 site results in the migrations being looped over.

From migrate:upgrade:

--------------------------------------------------------------------------------- 
 Generated migrations                                                             
--------------------------------------------------------------------------------- 
 upgrade_book_settings                                                            
 upgrade_commerce1_cart_settings                                                  
 upgrade_commerce1_shipping_flat_rate                                             
 upgrade_commerce1_tax_type                                                       

When migrate:import runs it shows the following:

[notice] Processed 1 item (1 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_book_settings'
[notice] Processed 1 item (1 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_book_settings'
[notice] Processed 1 item (1 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_commerce1_cart_settings'
[notice] Processed 1 item (1 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_book_settings'
[notice] Processed 1 item (1 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_commerce1_cart_settings'
[notice] Processed 31 items (31 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_commerce1_shipping_flat_rate'
[notice] Processed 1 item (1 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_book_settings'
[notice] Processed 1 item (1 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_commerce1_cart_settings'
[notice] Processed 31 items (31 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_commerce1_shipping_flat_rate'
[notice] Processed 0 items (0 created, 0 updated, 0 failed, 0 ignored) - done with 'upgrade_commerce1_tax_type'

As you can see, it starts with the first item, upgrade_book_settings. When it goes to process the second item, upgrade_commerce1_cart_settings, it first outputs upgrade_book_settings a second time. When it goes to run the third item, upgrade_commerce1_shipping_flat_rate, it loops over the first two items again. This repeats until it finally hits an out-of-memory error on the 129th item of a migration with 202 tasks.

To Reproduce
ddev drush migrate:upgrade
ddev drush migrate:import --group='migrate_drupal_7'

Expected behavior
The migration to run once.

Actual behavior
The migration loops incrementally as it processes each new task.

Workaround
Revert to Drush 10.3.x.

System Configuration

Q	A
Drush version?	Latest 10.6.x stable release.
Drupal version?	9.2.7
PHP version	7.4
OS?	Mac, though the Drush command is running inside ddev.

Additional information
TBD.

[claudiu-cristea]

What command do you run?

[damienmckenna]

ddev drush migrate:import --group='migrate_drupal_7', like the "to reproduce" details indicate.

[weitzman]

Any chance this command adds more batches as it goes? If yes it could be hitting a bug we just fixed #4886

[damienmckenna]

That sounds like it might have been the problem.

Does this mean it won't be fixed in 10.x?

[damienmckenna]

I created a PR with the fix against 10.x - #4893.

[weitzman]

fixed in #4983