Latest version(s) requires Java 21, breaks compatibility on many systems

[mkempenaar]

Describe the issue
The latest version(s) of SnpEff (at least version 5.2e) requires Java version 21 while many systems still operate on Java version 17 (LTS).
Old versions are not available from the website (links to: https://sourceforge.net/projects/snpeff/files/ where version 4.3t is the latest)

To Reproduce

1. SnpEff version: v5.2e
2. Genome version: --
3. SnpEff full command line: Running on a system with Java 17 installed: java -jar snpEff.jar
4. Output / Error message: Error: LinkageError occurred while loading main class org.snpeff.SnpEff java.lang.UnsupportedClassVersionError: org/snpeff/SnpEff has been compiled by a more recent version of the Java Runtime (class file version 65.0), this version of the Java Runtime only recognizes class file versions up to 61.0

Expected behavior

• Given the documentation on the SnpEff website that lists the following system requirement: SnpEff requires that you have Java v1.11 or later installed, it is expected to run with Java version 17 installed (which is for instance the latest official version available from the Debian repository).

Is there a specific reason why the latest version has been compiled with Java 21? Solutions for now can include:

• Update the system requirements
• Change to link to 'older versions' to the releases available here on Github

[Maggeok]

I have just experienced the same error:

java -jar snpEff.jar build -gff3 -v Afum_ref
Error: LinkageError occurred while loading main class org.snpeff.SnpEff
java.lang.UnsupportedClassVersionError: org/snpeff/SnpEff has been compiled by a more recent version of the Java Runtime (class file version 65.0), this version of the Java Runtime only recognizes class file versions up to 55.0

I did the obvious - used the older version, yet that might be an obstacle that will influence many users.