Running 20 tests (2023-04-10 12:04:22-0400, selector `(not (or (tag :expensive-test) (tag :unstable)))')
Test wallpaper--find-command-args/return-list backtrace:
  signal(ert-test-failed (((should (or (not (wallpaper--find-command-a
  ert-fail(((should (or (not (wallpaper--find-command-args)) (listp (w
  #f(compiled-function () #<bytecode -0xf1c8e61287de8c8>)()
  ert--run-test-internal(#s(ert--test-execution-info :test #s(ert-test
  ert-run-test(#s(ert-test :name wallpaper--find-command-args/return-l
  ert-run-or-rerun-test(#s(ert--stats :selector (not ...) :tests [... 
  ert-run-tests((not (or (tag :expensive-test) (tag :unstable))) #f(co
  ert-run-tests-batch((not (or (tag :expensive-test) (tag :unstable)))
  ert-run-tests-batch-and-exit((not (or (tag :expensive-test) (tag :un
  command-line-1(("-L" ":." "-l" "ert" "-l" "lisp/image/wallpaper-test
  command-line()
  normal-top-level()
Test wallpaper--find-command-args/return-list condition:
    (ert-test-failed
     ((should
       (or
	(not ...)
	(listp ...)))
      :form
      (or
       (not
	(wallpaper--find-command-args))
       (listp
	(wallpaper--find-command-args)))
      :value nil))
   FAILED   1/20  wallpaper--find-command-args/return-list (0.000127 sec) at lisp/image/wallpaper-tests.el:128
   passed   2/20  wallpaper--find-command/return-string (0.000064 sec)
   passed   3/20  wallpaper--find-setter (0.000203 sec)
   passed   4/20  wallpaper--find-setter/call-predicate (0.000192 sec)
   passed   5/20  wallpaper--find-setter/set-current-setter (0.000182 sec)
   passed   6/20  wallpaper--format-arg/filename (0.000410 sec)
   passed   7/20  wallpaper--format-arg/filename-hex (0.011550 sec)
   passed   8/20  wallpaper--format-arg/height (0.000092 sec)
   passed   9/20  wallpaper--format-arg/monitor (0.000076 sec)
   passed  10/20  wallpaper--format-arg/screen (0.000065 sec)
   passed  11/20  wallpaper--format-arg/width (0.000063 sec)
   passed  12/20  wallpaper--format-arg/workspace (0.000072 sec)
   passed  13/20  wallpaper--get-default-file/empty-gives-nil (0.006245 sec)
   passed  14/20  wallpaper--get-default-file/file-at-point (0.004047 sec)
   passed  15/20  wallpaper--get-default-file/visiting-file (0.000751 sec)
   passed  16/20  wallpaper--image-file-regexp/return-string (0.000099 sec)
Desktop wallpaper changed to /tmp/emacs-test-ZMjmPd.jpg
   passed  17/20  wallpaper-set/calls-init-action (0.001781 sec)
   passed  18/20  wallpaper-set/calls-wallpaper-set-function (0.000297 sec)
Desktop wallpaper changed to /tmp/emacs-test-sf7h0n.jpg
   passed  19/20  wallpaper-set/runs-command (0.002194 sec)
   passed  20/20  wallpaper-set/runs-command/detach (0.002114 sec)

Ran 20 tests, 19 results as expected, 1 unexpected (2023-04-10 12:04:22-0400, 0.086526 sec)

1 unexpected results:
   FAILED  wallpaper--find-command-args/return-list