update-notifier-release upstart job logs excessively

Here's some contents from a log file:

Thu Apr 3 15:52:42 PDT 2014 new release available
Fri Apr 4 09:47:44 PDT 2014 new release available
Fri Apr 4 09:47:55 PDT 2014 new release available
Fri Apr 4 10:24:37 PDT 2014 new release available

Actually, the frequency this is logging is really quite odd too.

Mon Apr 14 14:43:40 PDT 2014 new release available
Mon Apr 14 14:44:38 PDT 2014 new release available
Mon Apr 14 14:44:39 PDT 2014 new release available
Mon Apr 14 14:45:34 PDT 2014 new release available
Mon Apr 14 16:22:42 PDT 2014 new release available

I rebooted my system at about 14:43, and then ssh'ed into it from another system at 16:22. As noted earlier /var/lib/ubuntu-release-upgrader/release-upgrade-available is used to determine if a new release is available, that file is created by /usr/lib/ubuntu-release-upgrader/release-upgrade-motd which is called by /etc/update-motd.d/91-release-upgrade so it seems like something is wrong with release-upgrade-motd or how often it is called.

Maybe I'm misreading this, but would:
"""
=== modified file 'debian/update-notifier-release.conf'
--- debian/update-notifier-release.conf 2013-06-03 22:40:21 +0000
+++ debian/update-notifier-release.conf 2014-04-15 06:32:33 +0000
@@ -8,9 +8,9 @@

 script
-DATE=$(date)
-echo "$DATE new release available"
 if [ -s $FILE ]; then
+ DATE=$(date)
+ echo "$DATE new release available"
     # use the --devel switch to check for a devel release
     /usr/lib/ubuntu-release-upgrader/check-new-release-gtk
 fi
"""

be enough? The /var/lib/ubuntu-release-upgrader/release-upgrade-available file serves as a "stamp" file that is used to record the last check time and as the actual information that is displayed to the user (if the file is non-empty). The debian/release-upgrade-motd runs daily to check for a new release so the file is touched daily but a new release is only there if the file is non-empty.

Yes, that would be enough to fix the messages appearing in the log file, but my last comment was more about why is the create event happening so often?

# release-upgrade-available is provided by /usr/lib/ubuntu-release-upgrader/release-upgrade-motd
start on (
    file FILE=/var/lib/ubuntu-release-upgrader/release-upgrade-available EVENT=create
)

I believe the intent of the release-upgrade-motd is to only check for a new release at most once per day, and based off the data in the log file (comment 3) it is being checked for more than that (or the file is being "created").

Aha, thanks Brian. Yeah, this is indeed interessting.