Why do errors like "lookup_mount: exports lookup failed for <hostname>" appear in /var/log/messages on NFS clients configured to use autofs?

Issue

• automount produces errors in /var/log/messages on the client side whenever an NFS share is accessed:

  Jan 27 09:25:07 <hostname> automount[2722]: lookup_mount: exports lookup failed for psadl9 
  Jan 27 09:25:07 <hostname> automount[2722]: create_udp_client:90: hostname lookup failed: Operation not permitted 
  Jan 27 09:25:07 <hostname> automount[2722]: create_tcp_client:299: hostname lookup failed: Operation not permitted 
  
  Jan 27 10:32:43 <hostname> automount[2851]: lookup_mount: exports lookup failed for psadl9 
  Jan 27 10:32:43 <hostname> automount[2851]: create_udp_client:90: hostname lookup failed: Operation not permitted 
  Jan 27 10:32:43 <hostname> automount[2851]: create_tcp_client:299: hostname lookup failed: Operation not permitted