entity-read fails on Drupal 8

Probably all but at least the following commands fail on Drupal 8

drush entity-read file `drush entity-read file`
drush entity-read comment `drush entity-read comment`
drush entity-read user `drush entity-read user`

I have added tests to our simple test script to see for yourself.

See also devel generate #1375800: Fatal error: Call to undefined method stdClass::save() when generating comments where comments are now real classes.