Backport OpenJDK

Ubuntu follows an N-2 policy for OpenJDK backports. Under this policy, a new stable (LTS) release introduced in Ubuntu version N is backported to the current LTS release and the two preceding LTS releases.

Interim OpenJDK releases (the non-LTS releases published every six months) are strictly for the current development version of Ubuntu and are not backported to older releases.

jtreg packages

Each OpenJDK release depends on a specific version of jtreg<N> versioned package. TEST.ROOT files in the upstream source tree define the minimal required version. Run make -f debian/rules update-control-files to regenerate debian/control and set the version requirement of jtreg<N> dependency. Ensure that a minimal required version of jtreg<N> is available in the target release before backporting OpenJDK.

The jtreg package is maintained on Salsa: jtreg8. It uses an exception from Java policy that allows vendoring of jtreg dependencies.

Regenerate control files

OpenJDK debian/rules provides update-control-files target that regenerates files using the current Debian or Ubuntu release. Ensure that lsb_release is installed so that the target can determine the current release.

$ lsb_release --codename && make -f debian/rules update-control-files

Build the source package and upload

Follow the standard procedure to build the package locally (How to build packages locally) and upload the source package (Uploading to the Archive) to the staging PPA.