Posted by peterk on Aug 15, 2023; 12:18am
URL: https://forum.jogamp.org/Gluegen-download-issue-tp4042846p4042850.html

This other URL succeeded.

git clone --recurse-submodules git://jogamp.org/srv/scm/gluegen.git gluegen

I don't remember where I saw this one but it came up simply navigating your site.  I just tried it as listed in that document.
You might want to search and find it as it is out of sync somehow.

git clone --recurse-submodules https://jogamp.org/cgit/gluegen.git gluegen

Thanks for the correction.