After upgrade from Ubuntu 16.04 to 18.04 incron is broken.

[paulconstantine]

All settings remained the same. This is the job:

/var/www/html/www.zoootradio.com/htdocs/sites/default/files/feeds/ IN_MODIFY drush --root=/var/www/html/www.zoootradio.com/htdocs -y feeds-import music_artists

On a duplicate (still 16.04) box this works:

incrond[914]: (paulconstantine) CMD (drush --root=/var/www/html/www.zoootradio.com/htdocs -y feeds-import music_artists)

On the new 18.04 box this happens:

incrond[1931]: (paulconstantine) CMD (drush --root=/var/www/html/www.zoootradio.com/htdocs -y feeds-import music_artists)
incrond[7485]: cannot exec process: No such file or directory

Tried all kinds of things like adding tabs instead of a space, checked the directories and files again and again.

Just can't get this to work. What is the problem?

(the user paulconstantine is listed in /etc/incron.allow)

Can anyone help?

Cheers
Paul