Run the jar tool without arguments to see its usage. You pass it the -M option to create a JAR without a manifest. You won't be able to run the JAR file with java -jar, but you will still be able ...

How do you deploy a JAR file to Tomcat? Typically you deploy WAR files, not JARs. But if you need to link to a JAR file from a Java web app on Apache Tomcat, here's how to do it.

The Java Tutorials ‘ Deployment Trail features the Packaging Programs in JAR Files lesson that includes the relevant section Setting Package Version Information.

Since the SignatureEdDSA class is clearly package-private, if this is indeed the reason that Open Liberty is failing to load our jar-file, then that would seem to be a bug in Open Liberty.