No graph error

---

Look into /var/log/jenkins/jenkins.log

found error about:

WARNING: Error while serving http://jenkins.szabgab.com:8080/job/demo-flask-project/test/trend
...
Caused by: java.awt.AWTError: Assistive Technology not found: org.GNOME.Accessibility.AtkWrapper


Could not initialize class org.jfree.chart.JFreeChart
...
Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.jfree.chart.JFreeChart

Solution

sudo vim /etc/java-8-openjdk/accessibility.properties

Comment out the following line:

#assistive_technologies=org.GNOME.Accessibility.AtkWrapper

vim /etc/init.d/jenkins
add `-Djava.awt.headless=true` to the line

$SU -l $JENKINS_USER --shell=/bin/bash -c "$DAEMON $DAEMON_ARGS -- $JAVA $JAVA_ARGS -Djava.awt.headless=true -jar $JENKINS_WAR $JENKINS_ARGS" || return 2

systemctl daemon-reload
service jenkins restart