req-error.md
In httr2: Perform HTTP Requests and Process the Responses

can customise error info

Code
  req_perform(req)
Condition
  Error in `req_perform()`:
  ! HTTP 404 Not Found.
  i Hi!

long custom body is wrapped

Code
  req_perform(req)
Condition
  Error in `req_perform()`:
  ! HTTP 200 OK.
  i Ad aliquip et occaecat consequat eiusmod enim Lorem
    incididunt laboris deserunt. Consectetur magna ea ad quis
    dolore. Deserunt elit elit dolore magna fugiat ipsum id
    eu nostrud voluptate Lorem ad id anim. Cupidatat nulla
    ipsum irure nisi sunt ipsum commodo eu sint eiusmod
    consectetur.

failing callback still generates useful body

Failed to parse error body with method defined in `req_error()`.
Caused by error:
! This is an error!

Code
  req <- request_test("/status/404")
  req <- req_error(req, body = function(resp) resp_body_json(resp)$error)
  req_perform(req)
Condition
  Error in `req_perform()`:
  ! Failed to parse error body with method defined in `req_error()`.
  Caused by error in `resp_body_json()`:
  ! Unexpected content type "text/plain".
  * Expecting type "application/json" or suffix "json".