Cannot uninstall islandora module

[dannylamb]

From Islandora/jsonld#23

While uninstalling the core islandora module, this error occurs:

ubuntu@claw:/var/www/html/drupal/web/modules/contrib$ drupal module:uninstall islandora
 [ERROR] Attempt to create a field field_image that does not exist on entity type media.                                

It seems to be tied to the order in which our config entities get removed when uninstalling the module.

[whikloj]

References:
https://www.drupal.org/node/2661806

I've also seen this exception when working:
https://www.drupal.org/node/2622160

[whikloj]

I did some digging into this and it appears that the fields we add to the media entity type don't get stored.
I can't really explain it yet, but when we go to delete the fields on uninstallation. We end up in the FieldConfig classes preDelete method.
It hits this line.

$config['field_storage_uuid'] = $field->getFieldStorageDefinition()->uuid();

and then it runs to getFieldStorageDefinition()
where it fails to find any of our field names (field_mimetype, field_tn, field_height, etc) in the storage and throws the Exception.

So either we are not creating our fields correctly, or they are not expecting us to create fields...

[DiegoPino]

@whikloj nice catch! Probably we have some issue with the config entity. Will give it a look.

[whikloj]

Why is the field storage configured on the media instead of node like it is in islandora_image. Perhaps that is the problem?
ie.
field.storage.media.field_file.yml in islandora

versus

field.storage.node.field_jp2.yml in islandora_image.

[dannylamb]

@whikloj I think that's correct. field_file is is the file entity reference that Media have. The nodes have entity references to media that essentially correspond to datastream ids. FYI, in 8.4 drupal provides the file field for us (even has the same name), so we can drop it soon.

I'm wondering if it's just how we exported them? Maybe it would be beneficial to just rebuild and re-export to see if that fixes the error.

[dannylamb]

So I did a complete re-export just to make sure and the issue still persists. I dug even deeper and the issue appears to be that the field_storage is deleted before the field definition. When deleting the definition it needs to look up the storage and ka-boom.

All of our exported field definitions explicitly declare the storage as a dependency, which makes me worried that we're hitting a bug in core Drupal module uninstall code. 😞 It doesn't appear to be following the dependencies correctly.

[Natkeeran]

whikloj script can be used in the meantime to uninstall islandora. Note that MYSQL_USER has changed to drupal8: https://gist.github.com/whikloj/614fa21d7145b09197fd1e8513dd2f41

[whikloj]

I updated the script to use the drupal8 user by default. But of course you can customize it.