Update 8302 doesn't complete properly.

Problem/Motivation

Did composer update from 1.x to 3. latest. drush updb gives this output:

> [notice] Update started: field_group_update_8302
> [notice] If you want to use the Field Group accordion formatter, you will need to install the jQuery UI Accordion module.
> [notice] Update completed: field_group_update_8302

In ProcessBase.php line 188:

Unable to decode output into JSON: Syntax error

{
"0": {
"field_group": {
"8302": {
"results": {
"query": "If you want to use the Field Group accordion formatter, you will
need to install the → nk">jQuery UI Accordion module.",
"success": true
},
"type": "update"
}
}
},
"drush_batch_process_finished": true
}

I think the updat, which is pretty benign to begin with, did run.. just maybe not spitting out output properly. Or maybe this is a drush bug?

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes