autopkgtest fails in groovy on armhf

https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-groovy/groovy/armhf/d/dired-du/20200904_103020_fa428@/log.gz

...

Dired-Du mode disabled in Dired buffers
Test dired-du-sort-by-size backtrace:
  signal(ert-test-failed (((should (equal (quote ("filled-subdir" "ext
  ert-fail(((should (equal (quote ("filled-subdir" "external-file" "em
  (if (unwind-protect (setq value-107 (apply fn-105 args-106)) (setq f
  (let (form-description-109) (if (unwind-protect (setq value-107 (app
  (let ((value-107 (quote ert-form-evaluation-aborted-108))) (let (for
  (let* ((fn-105 (function equal)) (args-106 (condition-case err (let
  (let (filled-subdir-size empty-subdir-size file-size) (make-director
  (unwind-protect (let (filled-subdir-size empty-subdir-size file-size
  (let* ((dir (make-temp-file "dired-du" (quote dir))) (filled-subdir
  (closure (t) nil (let* ((dir (make-temp-file "dired-du" (quote dir))
  ert--run-test-internal(#s(ert--test-execution-info :test #s(ert-test
  ert-run-test(#s(ert-test :name dired-du-sort-by-size :documentation
  ert-run-or-rerun-test(#s(ert--stats :selector t :tests [#s(ert-test
  ert-run-tests(t #f(compiled-function (event-type &rest event-args) #
  ert-run-tests-batch(nil)
  ert-run-tests-batch-and-exit()
  eval((ert-run-tests-batch-and-exit))
  command-line-1(("-l" "package" "--eval" "(add-to-list 'package-direc
  command-line()
  normal-top-level()
Test dired-du-sort-by-size condition:
    (ert-test-failed
     ((should
       (equal '...
 (dired-get-marked-files ...)))
      :form
      (equal
       ("filled-subdir" "external-file" "empty-subdir")
       ("filled-subdir" "empty-subdir" "external-file"))
      :value nil :explanation
      (list-elt 1
  (arrays-of-different-length 13 12 "external-file" "empty-subdir" first-mismatch-at 1))))
   FAILED 2/7 dired-du-sort-by-size
...

Reported at upstream at:
https://github.com/calancha/dired-du/issues/4

The test is failing in LXC on amd64 as well, so IMO migration should not be block on this failure.