1. Catch the lightning talk summarizing the meeting here (you can even speed up 2x):

1. For a quick written summary, scroll down to the TL;DR section.

TL;DR This meeting took 3 hours and tackled a variety of topics related to DRM/KMS (Linux/DRM Kernel Modesetting):

• Sharing Drivers Between V4L2 and KMS: Brainstorming solutions for using a single driver for devices used in both camera capture and display pipelines.
• Real-Time Scheduling: Addressing issues with non-blocking page flips encountering sigkills under real-time scheduling.
• HDR/Color Management: Agreement on merging the current proposal, with NVIDIA implementing its special cases on VKMS and adding missing parts on top of Harry Wentland s (AMD) changes.
• Display Mux: Collaborative design discussions focusing on compositor control and cross-sync considerations.
• Better Commit Failure Feedback: Exploring ways to equip compositors with more detailed information for failure analysis.

---

Bringing together Linux display developers in the XDC 2024 While I didn t present a talk this year, I co-organized a Display/KMS meeting (with Rodrigo Siqueira of AMD) to build upon the momentum from the 2024 Linux Display Next hackfest. The meeting was attended by around 30 people in person and 4 remote participants. Speakers: Melissa Wen (Igalia) and Rodrigo Siqueira (AMD) Link: https://indico.freedesktop.org/event/6/contributions/383/ Topics: Similar to the hackfest, the meeting agenda was built over the first two days of the conference and mixed talks follow-up with new ideas and ongoing community efforts. The final agenda covered five topics in the scheduled order:

1. How to share drivers between V4L2 and DRM for bridge-like components (new topic);
2. Real-time Scheduling (problems encountered after the Display Next hackfest);
3. HDR/Color Management (ofc);
4. Display Mux (from Display hackfest and XDC 2024 talk, bringing AMD and NVIDIA together);
5. (Better) Commit Failure Feedback (continuing the last minute topic of the Display Next hackfest).

Unpacking the Topics Similar to the hackfest, the meeting agenda evolved over the conference. During the 3 hours of meeting, I coordinated the room and discussion rounds, and Rodrigo Siqueira took notes and also contacted key developers to provide a detailed report of the many topics discussed. From his notes, let s dive into the key discussions!

How to share drivers between V4L2 and KMS for bridge-like components. Led by Laurent Pinchart, we delved into the challenge of creating a unified driver for hardware devices (like scalers) that are used in both camera capture pipelines and display pipelines.

• Problem Statement: How can we design a single kernel driver to handle devices that serve dual purposes in both V4L2 and DRM subsystems?
• Potential Solutions:
  1. Multiple Compatible Strings: We could assign different compatible strings to the device tree node based on its usage in either the camera or display pipeline. However, this approach might raise concerns from device tree maintainers as it could be seen as a layer violation.
  2. Separate Abstractions: A single driver could expose the device to both DRM and V4L2 through separate abstractions: drm-bridge for DRM and V4L2 subdev for video. While simple, this approach requires maintaining two different abstractions for the same underlying device.
  3. Unified Kernel Abstraction: We could create a new, unified kernel abstraction that combines the best aspects of drm-bridge and V4L2 subdev. This approach offers a more elegant solution but requires significant design effort and potential migration challenges for existing hardware.

Real-Time Scheduling Challenges We have discussed real-time scheduling during this year Linux Display Next hackfest and, during the XDC 2024, Jonas Adahl brought up issues uncovered while progressing on this front.

• Context: Non-blocking page-flips can, on rare occasions, take a long time and, for that reason, get a sigkill if the thread doing the atomic commit is a real-time schedule.
• Action items:
  • Explore alternative backtraces during the busy wait (e.g., ftrace).
  • Investigate the maximum thread time in busy wait to reproduce issues faced by compositors. Tools like RTKit (mutter) can be used for better control (Michel D nzer can help with this setup).

HDR/Color Management This is a well-known topic with ongoing effort on all layers of the Linux Display stack and has been discussed online and in-person in conferences and meetings over the last years. Here s a breakdown of the key points raised at this meeting:

• Talk: Color operations for Linux color pipeline on AMD devices: In the previous day, Alex Hung (AMD) presented the implementation of this API on AMD display driver.
• NVIDIA Integration: While they agree with the overall proposal, NVIDIA needs to add some missing parts. Importantly, they will implement these on top of Harry Wentland s (AMD) proposal. Their specific requirements will be implemented on VKMS (Virtual Kernel Mode Setting driver) for further discussion. This VKMS implementation can benefit compositor developers by providing insights into NVIDIA s specific needs.
• Other vendors: There is a version of the KMS API applied on Intel color pipeline. Apart from that, other vendors appear to be comfortable with the current proposal but lacks the bandwidth to implement it right now.
• Upstream Patches: The relevant upstream patches were can be found here. [As humorously notes, this series is eagerly awaiting your Acked-by (approval)]
• Compositor Side: The compositor developers have also made significant progress.
  • KDE has already implemented and validated the API through an experimental implementation in Kwin.
  • Gamescope currently uses a driver-specific implementation but has a draft that utilizes the generic version. However, some work is still required to fully transition away from the driver-specific approach. AP: work on porting gamescope to KMS generic API
  • Weston has also begun exploring implementation, and we might see something from them by the end of the year.
• Kernel and Testing: The kernel API proposal is well-refined and meets the DRM subsystem requirements. Thanks to Harry Wentland effort, we already have the API attached to two hardware vendors and IGT tests, and, thanks to Xaver Hugl, a compositor implementation in place.

Finally, there was a strong sense of agreement that the current proposal for HDR/Color Management is ready to be merged. In simpler terms, everything seems to be working well on the technical side - all signs point to merging and shipping the DRM/KMS plane color management API!

Display Mux During the meeting, Daniel Dadap led a brainstorming session on the design of the display mux switching sequence, in which the compositor would arm the switch via sysfs, then send a modeset to the outgoing driver, followed by a modeset to the incoming driver.

• Context:
  • During this year Linux Display Next hackfest, Mario Limonciello (AMD) introduced the topic and led a discussion on Display Mux.
  • Daniel Dadap (NVIDIA) retook this discussion with the XDC 2024 talk: Dynamic Switching of Display Muxes on Hybrid GPU Systems.
• Key Considerations:
  • HPD Handling: There was a general consensus that disabling HPD can be part of the sequence for internal panels and we don t need to focus on it here.
  • Cross-Sync: Ensuring synchronization between the compositor and the drivers is crucial. The compositor should act as the drm-master to coordinate the entire sequence, but how can this be ensured?
  • Future-Proofing: The design should not assume the presence of a mux. In future scenarios, direct sharing over DP might be possible.
• Action points:
  • Sharing DP AUX: Explore the idea of sharing DP AUX and its implications.
  • Backlight: The backlight definition represents a problem in the mux switch context, so we should explore some of the current specs available for that.

Towards Better Commit Failure Feedback In the last part of the meeting, Xaver Hugl asked for better commit failure feedback.

• Problem description: Compositors currently face challenges in collecting detailed information from the kernel about commit failures. This lack of granular data hinders their ability to understand and address the root causes of these failures.

To address this issue, we discussed several potential improvements:

• Direct Kernel Log Access: One idea is to directly load relevant kernel logs into the compositor. This would provide more detailed information about the failure and potentially aid in debugging.
• Finer-Grained Failure Reporting: We also explored the possibility of separating atomic failures into more specific categories. Not all failures are critical, and understanding the nature of the failure can help compositors take appropriate action.
• Enhanced Logging: Currently, the dmesg log doesn t provide enough information for user-space validation. Raising the log level to capture more detailed information during failures could be a viable solution.

By implementing these improvements, we aim to equip compositors with the necessary tools to better understand and resolve commit failures, leading to a more robust and stable display system.

A Big Thank You! Huge thanks to Rodrigo Siqueira for these detailed meeting notes. Also, Laurent Pinchart, Jonas Adahl, Daniel Dadap, Xaver Hugl, and Harry Wentland for bringing up interesting topics and leading discussions. Finally, thanks to all the participants who enriched the discussions with their experience, ideas, and inputs, especially Alex Goins, Antonino Maniscalco, Austin Shafer, Daniel Stone, Demi Obenour, Jessica Zhang, Joan Torres, Leo Li, Liviu Dudau, Mario Limonciello, Michel D nzer, Rob Clark, Simon Ser and Teddy Li. This collaborative effort will undoubtedly contribute to the continued development of the Linux display stack. Stay tuned for future updates!

Changes in RcppArmadillo version 14.2.0-1 (2024-11-16)

• Upgraded to Armadillo release 14.2.0 (Smooth Caffeine)
  • Faster handling of symmetric matrices by inv() and rcond()
  • Faster handling of hermitian matrices by inv(), rcond(), cond(), pinv(), rank()
  • Added solve_opts::force_sym option to solve() to force the use of the symmetric solver
  • More efficient handling of compound expressions by solve()
• Added exporter specialisation for icube for the ARMA_64BIT_WORD case

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

The Reproducible Builds community sadly announces it has lost its founding member. J r my Bobbio aka Lunar passed away on Friday November 8th in palliative care in Rennes, France. Lunar was instrumental in starting the Reproducible Builds project in 2013 as a loose initiative within the Debian project. Many of our earliest status reports were written by him and many of our key tools in use today are based on his design. Lunar was a resolute opponent of surveillance and censorship, and he possessed an unwavering energy that fueled his work on Reproducible Builds and Tor. Without Lunar s far-sightedness, drive and commitment to enabling teams around him, Reproducible Builds and free software security would not be in the position it is in today. His contributions will not be forgotten, and his high standards and drive will continue to serve as an inspiration to us as well as for the other high-impact projects he was involved in. Lunar s creativity, insight and kindness were often noted. He will be greatly missed.

Other tributes:

• Anargeek.net [FR]
• LWN
• Debian
• Stefano Zacchiroli
• Linuxfr.org [FR]
• Software Heritage
• A history of the Reproducible Builds project

Complexity Culture In a large enough organization, where the team is high functioning enough to have and maintain trust amongst peers, members of the team will specialize. People will begin to engage with subsets of the work to be done, and begin to have their efficacy measured against that part of the organization s problems. Incentives shift, and over time it becomes increasingly likely that two engineers may have two very different priorities when working on the same system together. Someone accountable for uptime and tasked with responding to outages will begin to resist changes. Someone accountable for rapidly delivering features will resist gates between them and their users. Companies (either wittingly or unwittingly) will deal with this by tasking engineers with both production (feature development) and operational tasks (maintenance), so the difference in incentives isn t usually as bad as it could be. When we get a bunch of folks from far-flung corners of an organization in a room, fire up a slide deck and throw up some aspirational to-be architecture diagram in order to get a sign-off to solve some problem (be it someone needs a credible promotion packet, new feature needs to get delivered, or the system has begun to fail and needs fixing), the initial reaction will, more often than I d like, start to devolve into a discussion of how this is going to introduce a bunch of complexity, going to be hard to maintain, why can t you make it less complex? Right around here is when I start to try and contextualize the conversation happening around me understand what complexity is that being discussed, and understand who is taking on that burden. Think about who should be owning that problem, and work through the tradeoffs involved. Is it best solved here, or left to consumers (be them other systems, developers, or users). Should something become an API call s optional param, taking on all the edge-cases and on, or should users have to implement the logic using the data you return (leaving everyone else to take on all the edge-cases and maintenance)? Should you process the data, or require the user to preprocess it for you? Frequently it s right to make an active and explicit decision to simplify and leave problems to be solved downstream, since they may not actually need to be solved or perhaps you expect consumers will want to own the specifics of how the problem is solved, in which case you leave lots of documentation and examples. Many other times, especially when it s something downstream consumers are likely to hit, it s best solved internal to the system, since the only thing that can come of leaving it unsolved are bugs, frustration and half-correct solutions. This is a grey-space of tradeoffs, not a clear decision tree. No one wants the software manifestation of a katamari ball or a junk drawer, nor does anyone want a half-baked service unable to handle the simplest use-case.

Head-in-sand as a Service Popoffs about how complex something is, are, to a first approximation, best understood as meaning complicated for the person making comments . A lot of the #thoughtleadership believe that an AWS hosted EKS k8s cluster running images built by CI talking to an AWS hosted PostgreSQL RDS is not complex. They re right. Mostly right. This is less complex less complex for them. It s not, however, without complexity and its own tradeoffs it s just complexity that they do not have to deal with. Now they don t have to maintain machines that have pesky operating systems or hard drive failures. They don t have to deal with updating the version of k8s, nor ensuring the backups work. No one has to push some artifact to prod manually. Deployments happen unattended. You click a button and get a cluster. On the other hand, developers outside the ops function need to deal with troubleshooting CI, debugging access control rules encoded in turing complete YAML, permissions issues inside the cluster due to whatever the fuck a service mesh is, everyone needs to learn how to use some k8s tools they only actually use during a bad day, likely while doing some x.509 troubleshooting to connect to the cluster (an internal only endpoint; just port forward it) not to mention all sorts of rules to route packets to their project (a single repo s binary being run in 3 containers on a single vm host). Beyond that, there s the invisible complexity complexity on the interior of a service you depend on. I think about the dozens of teams maintaining the EKS service (which is either run on EC2 instances, or alternately, EC2 instances in a trench coat, moustache and even more shell scripts), the RDS service (also EC2 and shell scripts, but this time accounting for redundancy, backups, availability zones), scores of hypervisors pulled off the shelf (xen, kvm) smashed together with the ones built in-house (firecracker, nitro, etc) running on hardware that has to be refreshed and maintained continuously. Every request processed by network ACL rules, AWS IAM rules, security group rules, using IP space announced to the internet wired through IXPs directly into ISPs. I don t even want to begin to think about the complexity inherent in how those switches are designed. Shitloads of complexity to solve problems you may or may not have, or even know you had. What s more complex? An app running in an in-house 4u server racked in the office s telco closet in the back running off the office Verizon line, or an app running four hypervisors deep in an AWS datacenter? Which is more complex to you? What about to your organization? In total? Which is more prone to failure? Which is more secure? Is the complexity good or bad? What type of Complexity can you manage effectively? Which threaten the system? Which threaten your users?

COMPLEXIVIBES This extends beyond Engineering. Decisions regarding what tools are we able to use be them existing contracts with cloud providers, CIO mandated SaaS products, a list of the only permissible open source projects will incur costs in terms of expressed complexity . Pinning open source projects to a fixed set makes SBOM production less complex . Using only one SaaS provider s product suite (even if its terrible, because it has all the types of tools you need) makes accreditation less complex . If all you have is a contract with Pauly T s lowest price technically acceptable artisinal cloudary and haberdashery, the way you pay for your compute is less complex for the CIO shop, though you will find yourself building your own hosted database template, mechanism to spin up a k8s cluster, and all the operational and technical burden that comes with it. Or you won t and make it everyone else s problem in the organization. Nothing you can do will solve for the fact that you must now deal with this problem somewhere because it was less complicated for the business to put the workloads on the existing contract with a cut-rate vendor. Suddenly, the decision to reduce complexity because of an existing contract vehicle has resulted in a huge amount of technical risk and maintenance burden being onboarded. Complexity you would otherwise externalize has now been taken on internally. With a large enough organizations (specifically, in this case, i m talking about you, bureaucracies), this is largely ignored or accepted as normal since the personnel cost is understood to be free to everyone involved. Doing it this way is more expensive, more work, less reliable and less maintainable, and yet, somehow, is, in a lot of ways, less complex to the organization. It s particularly bad with bureaucracies, since screwing up a contract will get you into much more trouble than delivering a broken product, leaving basically no reason for anyone to care to fix this. I can t shake the feeling that for every story of technical mandates gone awry, somewhere just out of sight there s a decisionmaker optimizing for what they believe to be the least amount of complexity least hassle, fewest unique cases, most consistency as they can. They freely offload complexity from their accreditation and risk acceptance functions through mandates. They will never have to deal with it. That does not change the fact that someone does.

TC;DR (TOO COMPLEX; DIDN T REVIEW) We wish to rid ourselves of systemic Complexity after all, complexity is bad, simplicity is good. Removing upper-bound own-goal complexity ( accidental complexity in Brooks s terms) is important, but once you hit the lower bound complexity, the tradeoffs become zero-sum. Removing complexity from one part of the system means that somewhere else maybe outside your organization or in a non-engineering function must grow it back. Sometimes, the opposite is the case, such as when a previously manual business processes is automated. Maybe that s a good idea. Maybe it s not. All I know is that what doesn t help the situation is conflating complexity with everything we don t like legacy code, maintenance burden or toil, cost, delivery velocity.

• Complexity is not the same as proclivity to failure. The most reliable systems I ve interacted with are unimaginably complex, with layers of internal protection to prevent complete failure. This has its own set of costs which other people have written about extensively.
• Complexity is not cost. Sometimes the cost of taking all the complexity in-house is less, for whatever value of cost you choose to use.
• Complexity is not absolute. Something simple from one perspective may be wildly complex from another. The impulse to burn down complex sections of code is helpful to have generally, but sometimes things are complicated for a reason, even if that reason exists outside your codebase or organization.
• Complexity is not something you can remove without introducing complexity elsewhere. Just as not making a decision is a decision itself; choosing to require someone else to deal with a problem rather than dealing with it internally is a choice that needs to be considered in its full context.

Next time you re sitting through a discussion and someone starts to talk about all the complexity about to be introduced, I want to pop up in the back of your head, politely asking what does complex mean in this context? Is it lower bound complexity? Is this complexity desirable? Is what they re saying mean something along the lines of I don t understand the problems being solved, or does it mean something along the lines of this problem should be solved elsewhere? Do they believe this will result in more work for them in a way that you don t see? Should this not solved at all by changing the bounds of what we should accept or redefine the understood limits of this system? Is the perceived complexity a result of a decision elsewhere? Who s taking this complexity on, or more to the point, is failing to address complexity required by the problem leaving it to others? Does it impact others? How specifically? What are you not seeing? What can change? What should change?

for CLUSTER in $ CLUSTERS ; do
    pushd clusters/$ CLUSTER 
    # validate if we can create and build a flux-system like kustomization file
    kustomize create --autodetect --recursive
    if ! kustomize build . -o /dev/null 2> error.log; then
        echo "Error building flux-system kustomization for cluster $ CLUSTER "
        cat error.log
    fi
    popd
done

for CLUSTER in $ CLUSTERS ; do
    pushd clusters/$ CLUSTER 
    # validate if we can create and build a flux-system like kustomization file
    kustomize create --autodetect --recursive
    if ! kustomize build . -o /dev/null 2> error.log; then
        echo "Error building flux-system kustomization for cluster $ CLUSTER "
        cat error.log
    fi
    # validate if we always have a kustomization file in folders with yaml files
    for CLFOLDER in $(find . -type d); do
        test -f $ CLFOLDER /kustomization.yaml && continue
        test -f $ CLFOLDER /kustomization.yml && continue
        if [[ $(find $ CLFOLDER  -maxdepth 1 \( -name '*.yaml' -o -name '*.yml' \) -type f wc -l) != 0 ]]; then
            echo "Error Cluster $ CLUSTER  folder $ CLFOLDER  lacks a kustomization.yaml"
        fi
    done
    popd
done

This post is a review for Computing Reviews for Why academics under-share research data - A social relational theory , a article published in Journal of the Association for Information Science and Technology

Changes in inline version 0.3.20 (2024-11-10)

• Error message formatting is improved for compileCode (Alexis Derumigny in #25)
• Switch to using Authors@R, other general packaging maintenance for continuous integration and repository
• Use Rf_ in a handful of cases as R-devel now mandates it

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

1. Beyond bitwise equality for Reproducible Builds?
2. Two Ways to Trustworthy at SeaGL 2024
3. Number of cores affected Android compiler output
4. On our mailing list
5. diffoscope
6. IzzyOnDroid passed 25% reproducible apps
7. Distribution work
8. Website updates
9. Reproducibility testing framework
10. Supply-chain security at Open Source Summit EU
11. Upstream patches

Beyond bitwise equality for Reproducible Builds? Jens Dietrich, Tim White, of Victoria University of Wellington, New Zealand along with Behnaz Hassanshahi and Paddy Krishnan of Oracle Labs Australia published a paper entitled Levels of Binary Equivalence for the Comparison of Binaries from Alternative Builds :

The availability of multiple binaries built from the same sources creates new challenges and opportunities, and raises questions such as: Does build A confirm the integrity of build B? or Can build A reveal a compromised build B? . To answer such questions requires a notion of equivalence between binaries. We demonstrate that the obvious approach based on bitwise equality has significant shortcomings in practice, and that there is value in opting for alternative notions. We conceptualise this by introducing levels of equivalence, inspired by clone detection types.

A PDF of the paper is freely available.

Two Ways to Trustworthy at SeaGL 2024 On Friday 8th November, Vagrant Cascadian will present a talk entitled Two Ways to Trustworthy at SeaGL in Seattle, WA. Founded in 2013, SeaGL is a free, grassroots technical summit dedicated to spreading awareness and knowledge about free source software, hardware and culture. Vagrant s talk:

[ ] delves into how two project[s] approaches fundamental security features through Reproducible Builds, Bootstrappable Builds, code auditability, etc. to improve trustworthiness, allowing independent verification; trustworthy projects require little to no trust. Exploring the challenges that each project faces due to very different technical architectures, but also contextually relevant social structure, adoption patterns, and organizational history should provide a good backdrop to understand how different approaches to security might evolve, with real-world merits and downsides.

Number of cores affected Android compiler output Fay Stegerman wrote that the cause of the Android toolchain bug from September s report that she reported to the Android issue tracker has been found and the bug has been fixed.

the D8 Java to DEX compiler (part of the Android toolchain) eliminated a redundant field load if running the class s static initialiser was known to be free of side effects, which ended up accidentally depending on the sharding of the input, which is dependent on the number of CPU cores used during the build.

To make it easier to understand the bug and the patch, Fay also made a small example to illustrate when and why the optimisation involved is valid.

On our mailing list On our mailing list this month:

• Following-up to previous work, James Addison informed the list that the recently-released Sphinx documentation generator includes improvements to the next copyright notice substitutions.
• Pol Dellaiera wrote to the list in order to seek advice around introducing the concept of reproducibility to computer science Masters students at the University of Mons, Belgium.
• James Addison also followed-up to a previous thread on CONFIG_MODULE_SIG and the unreproducible Linux Kernel to add: I wonder whether it would be possible to use the Linux kernel s Integrity Policy Enforcement to deploy a policy that would prevent loading of anything except a set of expected kernel modules. [ ]
• There were also two informative replies from David Wheeler to a broad-based discussion on Reproducible Builds being defined in various standards. [ ][ ]

diffoscope diffoscope is our in-depth and content-aware diff utility that can locate and diagnose reproducibility issues. This month, Chris Lamb made the following changes, including preparing and uploading versions 279, 280, 281 and 282 to Debian:

• Ignore errors when listing .ar archives (#1085257). [ ]
• Don t try and test with systemd-ukify in the Debian stable distribution. [ ]
• Drop Depends on the deprecated python3-pkg-resources (#1083362). [ ]

In addition, Jelle van der Waa added support for Unified Kernel Image (UKI) files. [ ][ ][ ] Furthermore, Vagrant Cascadian updated diffoscope in GNU Guix to version 282. [ ][ ]

IzzyOnDroid passed 25% reproducible apps The IzzyOnDroid project has reached a good milestone by reaching over 25% of the ~1,200 Android apps provided by their repository (of official APKs built by the original application developers) having been confirmed to be reproducible by a rebuilder.

Distribution work In Debian this month:

• Holger Levsen uploaded devscripts version 2.24.2, including many changes to the debootsnap, debrebuild and reproducible-check scripts. This is the first time that debrebuild actually works (using sbuild s unshare backend). As part of this, Holger also fixed an issue in the reproducible-check script where a typo in the code led to incorrect results [ ]
• Recently, a news entry was added to snapshot.debian.org s homepage, describing the recent changes that made the system stable again:

  The new server has no problems keeping up with importing the full archives on every update, as each run finishes comfortably in time before it s time to run again. [While] the new server is the one doing all the importing of updated archives, the HTTP interface is being served by both the new server and one of the VM s at LeaseWeb.

  The entry list a number of specific updates surrounding the API endpoints and rate limiting.
• Lastly, 12 reviews of Debian packages were added, 3 were updated and 18 were removed this month adding to our knowledge about identified issues.

Elsewhere in distribution news, Zbigniew J drzejewski-Szmek performed another rebuild of Fedora 42 packages, with the headline result being that 91% of the packages are reproducible. Zbigniew also reported a reproducibility problem with QImage. Finally, in openSUSE, Bernhard M. Wiedemann published another report for that distribution.

Website updates There were an enormous number of improvements made to our website this month, including:

• Alba Herrerias:
  • Improve consistency across distribution-specific guides. [ ]
  • Fix a number of links on the Contribute page. [ ]
• Chris Lamb:
  • Correct the name of Civil Infrastructure Platform name and update image on the Projects page. [ ]
  • Update broken link on the Value Initialization page. [ ]
  • Try and make pipeline/branch builds of the website easier to browse. [ ][ ][ ][ ]
• hulkoba
  • Contribute to the new Success stories page. [ ]
• James Addison:
  • Huge and significant work on a (as-yet-merged) quickstart guide to be linked from the homepage [ ][ ][ ][ ][ ]
  • On the homepage, link directly to the Projects subpage. [ ]
  • Relocate dependency-drift notes to the Volatile inputs page. [ ]
• Ninette Adhikari:
  • Add a brand new Success stories page that highlights the success stories of Reproducible Builds, showcasing real-world examples of projects shipping with verifiable, reproducible builds . [ ][ ][ ][ ][ ][ ]
• Pol Dellaiera:
  • Update the website s README page for building the website under NixOS. [ ][ ][ ][ ][ ]
  • Add a new academic paper citation. [ ]

Lastly, Holger Levsen filed an extensive issue detailing a request to create an overview of recommendations and standards in relation to reproducible builds.

Reproducibility testing framework The Reproducible Builds project operates a comprehensive testing framework running primarily at tests.reproducible-builds.org in order to check packages and other artifacts for reproducibility. In October, a number of changes were made by Holger Levsen, including:

• Add a basic index.html for rebuilderd. [ ]
• Update the nginx.conf configuration file for rebuilderd. [ ]
• Document how to use a rescue system for Infomaniak s OpenStack cloud. [ ]
• Update usage info for two particular nodes. [ ]
• Fix up a version skew check to fix the name of the riscv64 architecture. [ ]
• Update the rebuilderd-related TODO. [ ]

In addition, Mattia Rizzolo added a new IP address for the inos5 node [ ] and Vagrant Cascadian brought 4 virt nodes back online [ ].

Supply-chain security at Open Source Summit EU The Open Source Summit EU took place recently, and covered plenty of topics related to supply-chain security, including:

• Public Sector & OpenSSF: Principles for Package Repository Security
• The Model Openness Framework: Promoting Completeness and Openness for Reproducibility, Transparency and Usability in AI
• Structured Scorecard Results: Tailor Your Own Supply-Chain Security Policies
• Lightning Talk: Elephant in the Room: How Supply Chain Security Standards Are Not Standard and What to Do About It
• Lightning Talk: Charting the Course for Secure Software Supply Chain with Guac-AI-Mole!
• TPMs, Merkle Trees and TEEs: Enhancing SLSA with Hardware-Assisted Build Environment Verification
• Accountability Taxonomy for AI Software Bill of Materials
• Securing Your Supply Chain with an Open Source Ecosystem
• OSS Supply Chain Threats and Why You Need a Holistic Security Strategy
• A Step Closer to in-Toto lly Secure: Using in-Toto and OPA Gatekeeper to Verify Artifact Integrity
• Panel Discussion: Improving Supply Chain Integrity with OpenSSF Technologies
• Case Study: 10+ Years of Developing an SBOM System and the Dos and Don ts
• SBOM in SaaS Environments: An Update
• Securing Git Repositories with Gittuf

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where appropriate. This month, we wrote a large number of such patches, including:

• Bernhard M. Wiedemann
  • apache-ivy (.zip modification time)
  • ccache (build failure)
  • colord (CPU)
  • efivar (CPU/march=native)
  • gsl (no check)
  • libcamera (date/copyright year)
  • libreoffice (possible rpm/build toolchain corruption bug)
  • moto (.gz modification time)
  • openssl-1_1 (date-related issue)
  • python-pygraphviz (benchmark)
  • sphinx/python-pygraphviz (benchmark)
  • python-panel (package.lock has random port)
  • python-propcache (random temporary path)
  • python314 (.gz-related modification time)
  • rusty_v8 (random .o files)
  • scapy (date)
  • wine (parallelism)
  • ibmtss (FTBFS-2026)
  • pymol (date)
  • pandas (ASLR)
  • linutil (drop date)
  • lsof (also filed in openSUSE: uname -r in LSOF_VSTR)
  • schily (also filed in openSUSE: uname -r)
  • superlu (nocheck)
  • util (random test failure)
  • ceph (year-2038 variation from embedded boost)
• Chris Lamb:
  • #1085097 filed against python-roborock.
  • #1085280 filed against pywayland.
  • #1085283 filed against readsb.
  • #1085381 filed against xraylarch.
• James Addison:
  • #1085112 filed against distro-info.
• Zbigniew J drzejewski-Szmek:
  • calibre (two sort issues) [ ][ ]

---

Finally, If you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

• IRC: #reproducible-builds on irc.oftc.net.
• Mastodon: @reproducible_builds@fosstodon.org
• Mailing list: rb-general@lists.reproducible-builds.org
• Twitter: @ReproBuilds

PASSWD      = /etc/passwd
SHADOW      = /etc/shadow

passwd:         files nis systemd
group:          files nis systemd
shadow:         files nis

#! /bin/sh
PATH=/usr/sbin:/usr/bin
# only watch the /etc/shadow file
if [ "$2" != "shadow" ]; then
  exit 0
fi
cd /var/yp   exit 3
sleep 2
make

# apt install incron
# echo root >> /etc/incron.allow
# incrontab -e

/etc    IN_MOVED_TO     /usr/local/sbin/shadow-change $@ $# $%

# journalctl _COMM=incrond
e.g.
Oct 01 12:21:56 kueppers incrond[6588]: starting service (version 0.5.12, built on Jan 27 2023 23:08:49)
Oct 01 13:43:55 kueppers incrond[6589]: table for user root created, loading
Oct 01 13:45:42 kueppers incrond[6589]: PATH (/etc) FILE (shadow) EVENT (IN_MOVED_TO)
Oct 01 13:45:42 kueppers incrond[6589]: (root) CMD ( /usr/local/sbin/shadow-change /etc shadow IN_MOVED_TO)

# dpkg-divert --local --rename --divert /usr/bin/yppasswd-disable /usr/bin/yppasswd
chmod a-rwx /usr/bin/yppasswd-disable

Debian Contributions: 2024-10 Contributing to Debian is part of Freexian s mission. This article covers the latest achievements of Freexian and their collaborators. All of this is made possible by organizations subscribing to our Long Term Support contracts and consulting services.

rebootstrap, by Helmut Grohne After significant changes earlier this year, the state of architecture cross bootstrap is normalizing again. More and more architectures manage to complete rebootstrap testing successfully again. Here are two examples of what kind of issues the bootstrap testing identifies. At some point, libpng1.6 would fail to cross build on musl architectures whereas it would succeed on other ones failing to locate zlib. Adding --debug-find to the cmake invocation eventually revealed that it would fail to search in /usr/lib/<triplet>, which is the default library path. This turned out to be a bug in cmake assuming that all linux systems use glibc. libpng1.6 also gained a baseline violation for powerpc and ppc64 by enabling the use of AltiVec there. The newt package would fail to cross build for many 32-bit architectures whereas it would succeed for armel and armhf due to -Wincompatible-pointer-types. It turns out that this flag was turned into -Werror and it was compiling with a warning earlier. The actual problem is a difference in signedness between wchar_t and FriBidChar (aka uint32_t) and actually affects native building on i386.

Miscellaneous contributions

• Helmut sent 35 patches for cross build failures.
• Stefano Rivera uploaded the Python 3.13.0 final release.
• Stefano continued to rebuild Python packages with C extensions using Python 3.13, to catch compatibility issues before the 3.13-add transition starts.
• Stefano uploaded new versions of a handful of Python packages, including: dh-python, objgraph, python-mitogen, python-truststore, and python-virtualenv.
• Stefano packaged a new release of mkdocs-macros-plugin, which required packaging a new Python package for Debian, python-super-collections (now in NEW review).
• Stefano helped the mini-DebConf Online Brazil get video infrastructure up and running for the event. Unfortunately, Debian s online-DebConf setup has bitrotted over the last couple of years, and it eventually required new temporary Jitsi and Jibri instances.
• Colin Watson fixed a number of autopkgtest failures to get ansible back into testing.
• Colin fixed an ssh client failure in certain cases when using GSS-API key exchange, and added an integration test to ensure this doesn t regress in future.
• Colin worked on the Python 3.13 transition, fixing problems related to it in 15 packages. This included upstream work in a number of packages (postgresfixture, python-asyncssh, python-wadllib).
• Colin upgraded 41 Python packages to new upstream versions.
• Carles improved po-debconf-manager: now it can create merge requests to Salsa automatically (created 17, new batch coming this month), imported almost all the packages with debconf translation templates whose VCS is Salsa (currently 449 imported), added statistics per package and language, improved command line interface options. Performed user support fixing different issues. Also prepared an abstract for the talk at MiniDebConf Toulouse.
• Santiago Ruano Rinc n continued the organization work for the DebConf 25 conference, to be held in Brest, France. Part of the work relates to the initial edits of the sponsoring brochure. Thanks to Benjamin Somers who finalized the French and English versions.
• Rapha l forwarded a couple of zim and hamster bugs to the upstream developers, and tried to diagnose a delayed startup of gdm on his laptop (cf #1085633).
• On behalf of the Debian Publicity Team, Anupa interviewed 7 women from the Debian community, old and new contributors. The interview was published in Bits from Debian.

• Accept+Bug report

Accept + Bug Report This option would allow a package to enter Debian (in unstable or experimental) with an automatically filed RC bug report. The RC bug would prevent the package from migrating to testing until the issues are addressed. To ensure compatibility with the BTS, which only accepts bug reports for existing packages, a delayed job (24 hours post-acceptance) would file the bug.

• Binary name changes - for instance if done to experimental not via new

• Remove dependency tree

a) the DAK removal tooling to remove the entire dependency tree
   after prompting the bug report author for confirmation, or
b) the system to auto-generate corresponding bug reports for all
   packages in the dependency tree.

Changes in Rcpp release version 1.0.13-1 (2024-11-01)

• Changes in Rcpp API:
  • Use read-only VECTOR_PTR and STRING_PTR only with with R 4.5.0 or later (Kevin in #1342 fixing #1341)
• Changes in Rcpp Deployment:
  • Authors@R is now used in DESCRIPTION as mandated by CRAN

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

• [1] https://etbe.coker.com.au/2024/04/26/convergence-vs-transference/
• [2] https://www.youtube.com/watch?v=IhYDtLzmRQI

• In 2022, for my Terraform support project, a bunch of logic, including the list of supported backend domains was moved from the frontend code to the backend. This also made it possible to dynamically change which projects can use which domains suffixes for their proxies.
• Then, early this year, I added support for zones restricted to a single project, because we wanted to use the proxy for the *.svc.toolforge.org Toolforge infrastructure domains instead of coming up with a new system for that use case. This also added suport for using different TLS certificates for different domains so that we would not have to have a single giant certificate with all the names.
• Finally, the last step was to add two new features to the proxy system: support for adding a proxy at the apex of a domain, as well as support for domains that are not managed in Designate (the Cloud VPS/OpenStack auth DNS service). In addition, we needed a bit of config to ensure http-01 challenges get routed to the acme-chief instance.

• [1] https://tinyurl.com/26geg4az
• [2] https://tinyurl.com/29n4hyvv
• [3] https://www.youtube.com/watch?v=VcufX8hZ5-o
• [4] https://tinyurl.com/2beb7ala
• [5] https://v8.dev/blog/control-flow-integrity
• [6] https://tinyurl.com/26p8hlcr
• [7] https://docs.kernel.org/next/x86/shstk.html
• [8] https://tinyurl.com/26ffcrho
• [9] https://www.youtube.com/watch?v=v-imW24OXLY
• [10] https://www.youtube.com/watch?v=zoX_S6d-XU4
• [11] https://tinyurl.com/ysqe79q7
• [12] https://tinyurl.com/258r74cl
• [13] https://www.youtube.com/watch?v=mg79n_ndR68
• [14] https://tinyurl.com/2xtu7kvv

• 18% used a custom postinst script
• 11% provided their ssh pub key for passwordless root login
• 50% of the jobs didn't included a desktop environment at all, the others used GNOME, XFCE or KDE or the Ubuntu desktop the most.
• The biggest ISO was a FAIme job which created a live ISO with a desktop and some additional packages This job took 30min to finish and the resulting ISO was 18G in size.

# semanage fcontext -l grep bin/cups-browsed
/usr/bin/cups-browsed                              regular file       system_u:object_r:cupsd_exec_t:s0 
# sesearch -A -s cupsd_t -c file -p write
allow cupsd_t cupsd_interface_t:file   append create execute execute_no_trans getattr ioctl link lock map open read rename setattr unlink write  ;
allow cupsd_t cupsd_lock_t:file   append create getattr ioctl link lock open read rename setattr unlink write  ;
allow cupsd_t cupsd_log_t:file   append create getattr ioctl link lock open read rename setattr unlink write  ;
allow cupsd_t cupsd_runtime_t:file   append create getattr ioctl link lock open read rename setattr unlink write  ;
allow cupsd_t cupsd_rw_etc_t:file   append create getattr ioctl link lock open read rename setattr unlink write  ;
allow cupsd_t cupsd_t:file   append create getattr ioctl link lock open read rename setattr unlink write  ;
allow cupsd_t cupsd_tmp_t:file   append create getattr ioctl link lock open read rename setattr unlink write  ;
allow cupsd_t faillog_t:file   append getattr ioctl lock open read write  ;
allow cupsd_t init_tmpfs_t:file   append getattr ioctl lock read write  ;
allow cupsd_t krb5_host_rcache_t:file   append create getattr ioctl link lock open read rename setattr unlink write  ; [ allow_kerberos ]:True
allow cupsd_t print_spool_t:file   append create getattr ioctl link lock open read relabelfrom relabelto rename setattr unlink write  ;
allow cupsd_t samba_var_t:file   append getattr ioctl lock open read write  ;
allow cupsd_t security_t:file   append getattr ioctl lock open read write  ;
allow cupsd_t security_t:file   append getattr ioctl lock open read write  ; [ allow_kerberos ]:True
allow cupsd_t usbfs_t:file   append getattr ioctl lock open read write  ;
# sesearch -A -s cupsd_t -c security
allow cupsd_t security_t:security check_context; [ allow_kerberos ]:True
allow cupsd_t security_t:security   check_context compute_av  ;
# sesearch -A -s cupsd_t -c capability
allow cupsd_t cupsd_t:capability net_bind_service; [ allow_ypbind ]:True
allow cupsd_t cupsd_t:capability   audit_write chown dac_override dac_read_search fowner fsetid ipc_lock kill net_bind_service setgid setuid sys_admin sys_rawio sys_resource sys_tty_config  ;
# sesearch -A -s cupsd_t -c capability2
allow cupsd_t cupsd_t:capability2   block_suspend wake_alarm  ;
# sesearch -A -s cupsd_t -c blk_file

• [1] https://threadreaderapp.com/thread/1838169889330135132.html
• [2] https://tinyurl.com/26rjd5ex
• [3] https://tinyurl.com/2ckyvpyq
• [4] https://packages.debian.org/sid/miniupnpc
• [5] https://wiki.debian.org/AppArmor/HowToUse