Ask SimRel project not to bump BREEs to Java 25

[merks]

Executive Summary:

I suggest that the Planning Council ask the SimRel projects to hold off bumping the BREE to Java 25 until a Temurin JDK for Java 25 is supported for all supported Platforms.

---

The rules for when SimRel projects can start using Java 25 leave a bit of room for interpretation.

• https://eclipse.dev/simrel/?file=wiki/SimRel/Simultaneous_Release_Requirements.md#execution-environment

Java 25 released September 16th. The 20260-93 release is March 11:

• https://eclipse.dev/simrel/?file=wiki/SimRel/2026-03.md

So that isn't quite 6 months (if you consult a lawyer).

In any case, I wouldn't really care except that Temurin has yet to produce a win32 aarch64 Java 25 release:

• jdk-25 Windows aarch64 aqa testcases "hang" or take a very long time... adoptium/aqa-tests#6623

So the JDK downloads for that are missing.

• https://adoptium.net/temurin/releases/?version=25

Therefore JustJ does not have such a thing either and as a result of that we would not be able to build installers and would not be able to build EPP packages for win32 aarch64 Java 25.

[HeikoKlare]

So that isn't quite 6 months (if you consult a lawyer).

Indeed. The requirements explicitly state:

And, going forward, the first Eclipse SimRel release to allow an LTS will be 6-9 months later.

This indicates to me that the idea is to have the next two releases still support the previous LTS (therefore the 6-9 months priod). In the current case, the first release to potentially use Java 25 would thus be 2026-06. Maybe my understanding is wrong and obviously the requirements are not precise enough on this, so we should definitely improve them.

In any case, I don't think that SimRel projects should be allowed to bump the BREE according to these requirements no matter what's going on around (e.g., compatibility problems with a new LTS or even the missing availability of a JDK build as we see here). That's why I agree with your opinion to ask to not bump to Java 25 for the 2026-03 release, no matter how the current requirements are interpreted.

[jonahgraham]

bumping the BREE to Java 25 until a Temurin JDK for Java 26 is supported for all supported Platforms.

The "26" in #75 (comment) is a typo?

[merks]

bumping the BREE to Java 25 until a Temurin JDK for Java 26 is supported for all supported Platforms.

The "26" in #75 (comment) is a typo?

Sorry, yes I edited the comment to fix it.

(For Java 26 beta we actually do have win32 aarch64 because the betas don't need to pass the TCKs.)

[HeikoKlare]

The topic was discussed in today's planning council meeting, see:

• Meeting Minutes for Planning Council 2025-12-03 #76

To deal with the situation, the following was proposed and agreed on by the participants:

• Do not allow SimRel participants to move to Java 25 for the Eclipse 2026-03 release
• Reevaluate the situation in February/March to see if Windows on ARM support needs to be dropped for 2026-06 or whether Java 25 will not be allowed for 2026-06 as well
• In case SimRel participants will be allowed to move to Java 25 for the 2026-06 release, the Platform (including SWT) will be as well

We encourage every planning council member to share their opinion and potential veto on this by Tuesday, 9th December 2025. If no concerns will be raised by then, the planning council will share this decision via the SimRel mailing list with the SimRel participants.

[HeikoKlare]

As agreed, information has been sent via simrel-dev mailing list: https://www.eclipse.org/lists/simrel-dev/msg00106.html

[jonahgraham]

@chirontt as you have previously contributed significantly in the past to support Windows on ARM I wanted to ensure that you saw this message as it both may affect you and perhaps you have insights on getting Windows on ARM JVMs resolved.

[chirontt]

@jonahgraham Sorry, I've never been to the JDK development/testing, so I'm of no help here.

[jonahgraham]

No worries @chirontt - I am glad you have seen this issue so that you are in the loop of what the project is doing with regards to this work. I hope you can continue to advocate for Windows on ARM users/developers, to whatever level you think is appropriate, so that we don't forget about them.