JIRA Field assignee cannot be set through Python

Question

I have a python application which uses the JIRA API to fetch the open JIRA issues. For one of the issue's, I want to change the status and assign a new user. Following the JIRA documentation, applied the transition as below

jira.transition_issue(issue, '21', fields={'assignee':{'name': 'user_name'})

However I get the following exception <text: Field 'assignee' cannot be set. It is not on the appropriate screen, or unknown.>

After digging through several public forums, where similar issue was posted, I checked the default create and edit screens to see if the assignee field appears and it does. To check if the user has privileged permissions I have tried to create an issue through API and it successfully created.I was also able to change the status of the issue through API and add/remove watchers. The problem only appears when trying to assign a user to the issue.

Can someone please help me here?

Thanks, kv

Answer 1

The problem is that assignee does not appear on the screen associated with the transition. If you add assignee to that transition screen, you should be able to set it this way.