I want to set the list of people on a custom field using the JIRA REST API.
According to https://developer.atlassian.com/jiradev/jira-apis/jira-rest-apis/jira-rest-api-tutorials/jira-rest-api-example-create-issue, the syntax for setting a UserPicker is:
"customfield_10017": { "name":"brollins" } and according to https://developer.atlassian.com/jiradev/jira-apis/jira-rest-apis/jira-rest-api-tutorials/updating-an-issue-via-the-jira-rest-apis, the JSON sent needs to specify an update followed by the fields.
So, the JSON I'm sending is:
{
'update': {
'fields':
{
'customfield_10800': [{'name': 'fred.bloggs@example.com'}]
}
}
}However, when I try to PUT this to the issue, I get the following message back:
Unexpected character (\'u\' (code 117)): expected a valid value (number, String, array, object, \'true\', \'false\' or \'null\')\\n at [Source: org.apache.catalina.connector.CoyoteInputStream@228b27b5; line: 1, column: 2]
Now, according to https://docs.atlassian.com/jira/REST/server/#api/2/issue-editIssue, fields should appear either in "fields" or "update" not in both. If I remove the "update" section, the error message changes to:
"Unrecognized token \'fields\': was expecting \'null\', \'true\', \'false\' or NaN\\n at [Source: org.apache.catalina.connector.CoyoteInputStream@228b27b5; line: 1, column: 8
I've tried double and single quotes.
I've run out of ideas 
What have I got wrong in the data that I'm sending?