This question is similar to this one. I know you need to have this plugin to support Java 15 in eclipse 2020-09, however, it doesn't seem to be available any longer.
When I try to install it via the marketplace, I am getting this error:
No repository found at https://download.eclipse.org/eclipse/updates/4.17-P-builds/.
Is there a way to install it from other sources?
I know that eclipse 2020-12 has been released, but we cannot use it due to bug #569498 (which didn't happen in eclipse 2020-09). So we would really need a way to install Java 15 support in eclipse 2020-09.
Because of regressions in 4.18, I decided to recreate 4.17-P-builds repository.
Please note this will be available till 4.19 is released or we decide to create a patch for 4.18 release.