What does it mean limited to exactly Java 8? The current package just ensures that a Java 8 or higher is installed, but you can also have Java 7, 9 or any other version installed and configured as the default for the machine. So, if I set the dependency on exactly Java 8 that only means that among my set of installed packages I must have java 8, but it does not ensure I do not have Java 9 also installed and configured. I can force to not have any other version of Java installed but that looks a bit too much to me. Why should jenkins prevent me to install any versions of java in my server as long as I have the right one for jenkins itself? So, I would recommend to:

• Drop the package's dependency on Java 8 and update the docs accordingly.
• Create a preinst script that checks if java 8 is the one configured for the jenkins user and print a warning or abort installation if not.

WDYT danielbeck?

Java 8 or higher

As Jenkins doesn't work with Java 9, this is just wrong. ≥8 should be =8. You can have others installed, but Jenkins doesn't have its dependencies satisfied if you only have 7 and 9. It needs 8.

danielbeck My point is that =8 alone doesn't really guarantees the installed jenkins to work, changing the >= 8 to =8 is feasible but IMHO a half backed solution that needs to be complemented by a preinst script by the resons specified above.

Preinst might be a bit much; doesn't the service script look for a compatible JRE?

I can not find anything like that on the debian init script It seems there are some checks in the case of RPM but I have not found anything in the debian one. Also to be sure I have installed the deb package in a machine with java 9 installed and configured as default and the service starts without problems and jenkins also does the same... see attached screenshot

Right, the deb hardcodes /usr/bin/java via https://github.com/jenkinsci/packaging/blob/master/deb/build/debian/jenkins.default#L7 – not sure this is desirable.

Happy to take your guidance on this, but I've seen multiple reports from people who got Java 9 installed through this dependency (I think on ubuntu 14.04 with custom repos? Not sure) and that should not be happening.