Element nuxeo-operation-button should display the error message thrown by the automation operation

When the called automation operation throw an exception with an error message, the nuxeo-operation-element only displays a generic error message and not the error message from the exception. Several users requested to display the error message in the toast.

I attached a Nuxeo package containing a Web UI button (element nuxeo-operation-button) that calls an automation operation that throws an exception with an error message if the input document is located in a certain workspace.

How to reproduce:

• install the attached Nuxeo package nuxeo-custom-operation-validate-document-package-1.0.0.zip in a LTS 2021 distibution and start it
• create a workspace /default-domain/workspaces/test-ws
• create a document in it and navigate to it
• click on the Validate Document button (checkmark icon)

Actual result: a toast with the message Error is displayed
Expected result: a toast with the message Oups! is displayed

You can build and start a Docker container with Docker Compose by cloning my Github repository nuxeo-custom-operation-validate-document.