When installing a new version of racket, run this script instead of just `raco pkg migrate <version-number-you-have-to-remember>`

raco-pkg-migrate.rkt

#!/usr/bin/racket
#lang racket/base

;;; License: [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0) or
;;;          [MIT license](http://opensource.org/licenses/MIT) at your option.

;; When installing a new version of Racket,
;; running this script setups all existing packages that had been installed
;; in the *user* scope.
;;
;; Notes:
;; * installation-wide packages are not migrated.
;;   In particular, bundled packages that were updated with `raco pkg update --link ...`,
;;   for example, will not be migrated and the bundled packages will take their place.
;;   (Moreover, since this script is run with the new version of Racket, it's difficult
;;   to discover these packages.)
;; * 'releases' and 'snapshot' packages are separated, and this script will migrate
;;   only from the same type.

(require racket/string
         racket/future
         pkg/path
         setup/setup)

(define h (read-pkgs-db 'user))

(define pkgs (hash-keys h))
(displayln (string-join (sort pkgs string<?) "\n"))

(setup #:pkgs pkgs #:make-doc-index? #t #:jobs (min (processor-count) 8)) ; no benefit after 8?