werkregie/doc/prs/2026-10-11-PR#20-temurin-25.md

PR#20: Temurin 25 for All werk Repositories

WARNING: This document describes only the change applied in this PR. It may already be outdated once the next PR is merged. Historic PR documentation is not maintained along with new PRs; treat it as a snapshot.

Problem

Each werk repository chooses its JDK and its Java runtime on its own, and each one differently:

• werkator, werkregie and the statistics service of werkrevisor pin Temurin 21 and download it with Foojay, in two different versions of the Foojay plugin.
• werkcrappit and werkbaum accept any JDK 21; werkprobe accepts any JDK and emits Java 17 bytecode.
• The build sandbox of Werkator has Debian's OpenJDK 21, whose jlinked runtime does not start on Hostsharing hosts.
• werkbaum runs on a full JDK in the home of its host, the others on a jlinked runtime.

mi decided on 2026-10-11 to choose one JDK and one runtime for all werk repositories.

Non-Goals

• No switch of a repository yet, also not of werkregie; each one gets a PR of its own.
• No change of Werkator's build environment yet.

Solution

• doc/adrs/0001-2026-10-11.temurin-25.md records the decision, the measurements and the order of the rollout.
• doc/adrs/0000-00-00.adr-template.md: the ADR template of Werkator.
• Werkbaum: #ops.jdk with the rollout steps.
• Version 0.8.1.