Qubes OS 4.2.0-rc5 is available for testing

We’re pleased to announce that the fifth release candidate (RC) for Qubes OS 4.2.0 is now available for testing. The ISO and associated verification files are available on the downloads page. For more information about the changes included in this version, see the full list of issues completed between RC4 and RC5 and the Qubes OS 4.2.0 release notes.

When is the stable release?

That depends on the number of bugs discovered in this RC and their severity. As explained in our release schedule documentation, our usual process after issuing a new RC is to collect bug reports, triage the bugs, and fix them. This usually takes around five weeks, depending on the bugs discovered. If warranted, we then issue a new RC that includes the fixes and repeat the whole process again. We continue this iterative procedure until we’re left with an RC that’s good enough to be declared the stable release. No one can predict, at the outset, how many iterations will be required (and hence how many RCs will be needed before a stable release), but we tend to get a clearer picture of this with each successive RC, which we share in this section in each RC announcement. Here is the latest update:

At this point, we are hopeful that RC5 will be the final RC.

Testing Qubes 4.2.0-rc5

Thank you to everyone who tested the previous Qubes 4.2.0 RCs! Due to your efforts, this new RC includes fixes for several bugs that were present in the previous RCs.

If you’re willing to test this new RC, you can help us improve the eventual stable release by reporting any bugs you encounter. We encourage experienced users to join the testing team.

A full list of issues affecting Qubes 4.2.0 is available here. We strongly recommend updating Qubes OS immediately after installation in order to apply all available bug fixes.

Upgrading to Qubes 4.2.0-rc5

If you’re currently running any Qubes 4.2.0 RC, you can upgrade to the latest RC by updating normally. However, please note that there have been some recent template changes, which are detailed in the Qubes OS 4.2.0 release notes.

If you’re currently on Qubes 4.1 and wish to test 4.2, please see how to upgrade to Qubes 4.2, which details both clean installation and in-place upgrade options. As always, we strongly recommend making a full backup beforehand.

Reminder: new signing key for Qubes OS 4.2

As a reminder, we published the following special announcement in Qubes Canary 032 on 2022-09-14:

We plan to create a new Release Signing Key (RSK) for Qubes OS 4.2. Normally, we have only one RSK for each major release. However, for the 4.2 release, we will be using Qubes Builder version 2, which is a complete rewrite of the Qubes Builder. Out of an abundance of caution, we would like to isolate the build processes of the current stable 4.1 release and the upcoming 4.2 release from each other at the cryptographic level in order to minimize the risk of a vulnerability in one affecting the other. We are including this notice as a canary special announcement since introducing a new RSK for a minor release is an exception to our usual RSK management policy.

As always, we encourage you to authenticate this canary by verifying its PGP signatures. Specific instructions are also included in the canary announcement.

As with all Qubes signing keys, we also encourage you to authenticate the new Qubes OS Release 4.2 Signing Key, which is available in the Qubes Security Pack (qubes-secpack) as well as on the downloads page under the Qubes OS 4.2.0-rc5 ISO.

What is a release candidate?

A release candidate (RC) is a software build that has the potential to become a stable release, unless significant bugs are discovered in testing. RCs are intended for more advanced (or adventurous!) users who are comfortable testing early versions of software that are potentially buggier than stable releases. You can read more about Qubes OS supported releases and the version scheme in our documentation.

This is a companion discussion topic for the original entry at https://www.qubes-os.org/news/2023/11/26/qubes-os-4-2-0-rc5-available-for-testing/

Thanks! The torrent of RC4 was seeded with a ratio of 56 (RC3 had 65), let’s seed RC5 !

However, I have an important question Where is “Split SSH management in Qubes Global Settings” ?


For anyone looking for the difference between RC4 and RC5, here are the issues closed after the release of RC4 (2023-10-13)

Issues closed after the release of RC4

Edit: OP was updated with full list of issues completed between RC4 and RC5


Well… did not work for me: an 4.2rc4 install only got elfutils and vim/xxd dom0 updates a few minutes ago, plus assorted template updates.
OS version remains 4.2rc4.

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Same here. Do we wait some more hours? I am on rc4 as well.

How did you check that btw? uname -a doesn’t show qubes os version.

Edit: Oh I can see the QubesOS version under Qubes OS Global Config > This Device window. It reports rc4 as well.

In Qube Manager → About (menu)


Edited to add: alternatively, in dom0, cat /etc/qubes-release


I think it would currently also show “rc4” if you install rc5 from the .iso:


Ugh. This is sloppy. :frowning_face:

I only came to the topic in wonder of why my rc4 (installed yesterday) which I updated just now was not reflecting rc5.

Turns out. Nobody gets rc5 in rc5 :eyes:

In seriousness. Thanks for the efforts in update. Was wondering why my dom0 had sooO many package updates.

/etc/os-release says R4.2 rc4 too

Thank you, @renehoj. I’ve been looking for a filter like closed:>2023-10-13 for a long time, but it’s nowhere to be found in GitHub’s documentation. It’s not even in their advanced search tool. I’m glad you pointed it out.

One problem with closed:>2023-10-13 is that it will continue to show all newer closed issues, including those closed after RC5 was released. However, thanks to your pointer, I stumbled upon this StackOverflow answer that shows how you can search for a range, e.g., closed:2023-10-13..2023-11-26. I’ve updated the link in the announcement in qubes-posts to use this feature:

Full list of issues completed between RC4 and RC5

Another difference is that I’ve removed the affects-4.2 and T: bug labels from the search, since we also care about enhancements and tasks, not just bugs. (Filtering by those labels was a necessary crutch before we had a way to filter by closure date, since we would’ve gotten non-4.2 results without them. We could have used affect-4.2 without T: bug, but it still wouldn’t have been accurate to say “all 4.2 issues,” since affects-* labels are usually used for bugs, not enhancements or tasks.)

This new search is much better, but it’s still not perfect, for a few reasons:

  • Completed issues are usually closed via commit messages, and there’s sometimes a significant time gap between the first commit that closes an issue and that change showing up in a usable package.
  • This search will also include non-release issues, like general documentation and website issues that happened to be completed within the closure date range.
  • Sometimes people forget to close issues when they complete them, and we close them only much later, when we realize that they’ve already been done for a long time.

Nonetheless, this should still be a pretty decent changelog.


I knew the link I posted as far from perfect, I wasn’t sure what labels to include or exclude. Not using any labels made it even worse, so I just added the date filter to the list from the announcement.

The link you posted does a much better job, I edited my post to avoid any confusion.


Yours was the missing piece that made it much more useful. Teamwork! :slight_smile:

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The only thing i experienced on RC5 was a failing whonix-gateway update running the Qubes Updater and i needed to use dpkg configure -a manually to fix it. But i think this is not related and can happen to anyone when updating with tor. Despite that everything works fine and smooth. I tested Whonix traffic, updating over tor, stream isolation per qube etc, and everything works like it should.

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Hello fellow testers,

I wanted to share my positive experience with testing Qubes OS 4.2.0-rc5. As an avid user of Qubes OS, I was thrilled to have the opportunity to try out the latest release candidate.

First and foremost, I must commend the development team for their dedication and hard work in bringing this version to life. The improvements and enhancements in Qubes OS 4.2.0-rc5 are truly remarkable. From the moment I started testing, I noticed a significant boost in performance and stability.

The attention to detail in Qubes OS 4.2.0-rc5 is evident. The user interface has been refined, making it more intuitive and user-friendly. I appreciate the clear and concise documentation provided, which made the testing process smooth and hassle-free.

In terms of security, Qubes OS continues to excel. The robust security features and compartmentalization of applications provide peace of mind, ensuring that my data and privacy are well-protected.

Overall, my testing experience with Qubes OS 4.2.0-rc5 has been exceptional. The improvements in performance and the continued focus on security make this release a significant step forward.

I would like to express my gratitude to the development team for their hard work and dedication in creating such a remarkable operating system. I am confident that Qubes final release will exceed expectations and provide users with an outstanding computing experience.

Thank you for the opportunity to test this release, and I look forward to seeing Qubes OS continue to evolve and innovate in the future.

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Yeah I appreciate the QubesOS devs and maintainers. However, the new UI’s for update are out of proportion with their buttons. Their buttons are larger than the ones in older UI’s for QubesOS management (like those that are found in [dom0] Qube Manager). Then, the new “Q menu”, again, is quite large, has lots of wasted whitespaces. And lastly, the Global Qube Settings UI, as well, suffers from large buttons, and large fonts. I have a thinkpad X230, and its screen is quite low resolution (1280 x 720, I guess), and in that screen, the UI looks uncomfortable.