How to reproduce:

Run in a systemd OS like CentOS 7 with

/etc/sysconfig/jenkins

JENKINS_JAVA_OPTIONS=-Dhudson.model.DirectoryBrowserSupport.CSP="default-src 'self';"

As per https://wiki.jenkins.io/display/JENKINS/Configuring+Content+Security+Policy

Error message in journalctl

Error: Could not find or load main class 'self';"

Investigation

This is because the last line of the systemd script /usr/lib/jenkins/jenkins-run is

$JAVA_CMD "${PARAMS[@]}"

and JAVA_CMD is composed of

JAVA_CMD="$JENKINS_JAVA_CMD $JENKINS_JAVA_OPTIONS -DJENKINS_HOME=$JENKINS_HOME -jar $JENKINS_WAR"

So the resulting command is

Result: java tries to load param #3 'self' as the main class and we get the error

Error: Could not find or load main class 'self';"

Documentation

That is because systemd Exec line splits on spaces unless the argument is wrapped in quotes see https://www.freedesktop.org/software/systemd/man/systemd.service.html#Command%20lines

So even if you add all sorts of quotes or escaping in JENKINS_JAVA_OPTIONS, it will still split on the spaces in the values of JENKINS_JAVA_OPTIONS, unless it is itself quoted in the Exec line.

systemd--

Suggested fix

The obvious fix, to me is to change the last line of /usr/lib/jenkins/jenkins-run to quote the $JENKINS_JAVA_OPTIONS, and I haven't tried it but I would suspect JENKINS_HOME and JENKINS_WAR with a space in their respective directory name to also fail the systemd service startup

Last line of /usr/lib/jenkins/jenkins-run could look like:

$JENKINS_JAVA_CMD "$JENKINS_JAVA_OPTIONS" "-DJENKINS_HOME=$JENKINS_HOME" -jar "$JENKINS_WAR" "${PARAMS[@]}"