Agenda brainstorming

Participants generated a list of topics and questions that they wanted to discuss at the meeting. The result of the brainstorming was then taken into account to identify the working sessions that had emerged as the most compelling for those in attendance.

Participants individually wrote questions of their interest on pieces of paper, then sorted them by topic as shown below and then everybody had 4 green dots to mark topics we wanted to further work on.

Marketing, etc. 1

  • how can we better communicate our progress to the public? ** green
  • are we making t-shirts ** green
  • should we aim to publish a paper on RB in an academic journal to gain more support?
  • write and sign RB manifesto ** green
  • talks/presentations and other “marketing”/outreach
  • how should we communicate the importance of reproducibility
  • how can we let even more developers know & care about reproducible builds?

Marketing, etc. 2

  • what made you see the value of repr. builds?
  • I do not see much commercial interest in RB, why? *** red
  • what % of a computer user’s problems are because of package mgmt/environment/reproduce
  • (discuss how to) get buy-in from projects that don’t yet take part in RB.
  • feedback results of to the developer


  • how can we become rich with Reproducible Builds? (or: Funding?) * green
  • Funding our work in 2019 + 2020 *** green
  • Funding reproducible builds
  • who is interested in sustainable funding for R-B
  • Create formal/legal organizational structure for R-B projects

Code signing & metadata

  • embedded signatures best practices ** green
  • signing packages vs. signing metadata * green
  • how to validate sources in 20 years? *** green
  • how to verify sources ** green

Technical end users

  • Develop user-interface to check for reproducibility ** green
  • other usertools than “do you really want to install that unreproducible package” * green
  • can users configure their system to only install verified reproducible packages? if not, what do we need? * green
  • What INTERFACES to build reproducibility info do we give to USERS? ** green
  • What tools can we provide to users to help them verify their software? ** green
  • End-user “prompts” re. unreproducible packages, interfaces, etc
  • client tools/strategy for verifying binaries
  • how to let users know if a package has been reproduced
  • who should be trusted when reproducible package is not actually reproducible? where to report suspicious build results? * green

End users (not necessarily technical end users)

  • Why is reprobuilds important for the end user?
  • what RB means for end users
  • which USERS should we expose build reproducibility info to? ** green
  • what’s the gain for the non-tech end user? * green

Newbie docs

  • Let’s have a “hello world!” tutorial! * green
  • Let’s make the documentation noob-friendy! ** green
  • Documentation for and questions from newcomers
  • Is there a list of common mistakes that makes packages/systems not reproducible? = 70% timestamps
  • What are the most common causes of non-reproducible builds ** green
  • Define the ambition of Reproducible Builds
  • How do we help projects define the SCOPE of their R.B. efforts? (e.g. inputs, build system variations…)


  • What parts of RB are too specific to Debian? is it worth changing them? * green
  • Rebuild Debian packages from the archive. * green
  • Let’s fork Debian?!! *** green, ** red
  • Debian: What is our next 1y realistic goal? 95.768%? Reproducible Installer ISO? Anything else?
  • reproducibng SOURCE debian package from git snapshot
  • Compatibility with signed .debs

What is reproducibility

  • can we do something about communities that cannot build dependencies from source? (npm, java, compiler builders?) : 1 green
  • if we make an image by deterministically composing snapshots of unreproducibly built data… do we call that image reproducible? : 1 green
  • how can we ensure the term “reproducible builds” is used consistently across the internet


  • make sure more computer architectures are supported
  • do we want/need reproducibility cross distributions? (“the i386 binary”)
  • reproducible cross-compiling (i.e. do we get the same as native compiling?) : 4 green


  • what tools can we all SHARE?
  • session/list/introduction about all tools/methods RB works with : 3 green
  • how far to bootstrap back the tools to be reproducible? : 1 green
  • fork squashfs
  • automated analysis of non-reproducible software (“linting”)
  • how can we let developrs test their software for reproducibility without external tools? : 2 green
  • overview/walkthrough of the Reproducible Builds tools landscape. (diffoscope/reprotest/disorderfs/s-nd) : 3 green


  • making Java software reproducible : 5 green
  • improve Maven packaging in Debian
  • what’s the status of reproducible builds in the Java/Android ecosystem?
  • easy to use F-Droid rebuilding by user
  • Tor Browser latest make it available in F-Droid

Binary artifact formats

  • let’s make comparison table of filesystem pack formats! (tar vs squashFS vs Ostree vs zip, cpio, etc) : 1 green
  • binary artifact explainer workshop : 1 green
  • sharing metadata about artifacts between different systems /apt, rpm, jar/ : 1 green
  • binary transparency — can we get it started? : 2 green
  • what should be the source of reproducible build? tarball, repository, something else…? : 3 green


  • create an overview of projects doing .buildinfo files : 1 green
  • should all distributions agree on the same buildinfo format, so that we can provide tools to work with them? : 4 green
  • require the .buildinfo file standard
  • best practice on .buildinfo
  • buildinfo storage for the next 6–12 months
  • buildinfo format for RPM
  • what’s the current status? what are solved problems / hard challenges?

System image

  • status of generating reproducible system images? : 4 green
  • reproducible debootstrap (basic OS image)
  • reproducible containers? : 1 green
  • reproducible Debian images eg. ISO images / etc. : 1 green
  • how do we build reproducible system images? : 1 green
  • are reproducible packages = reproducible OS? What about configuration?


  • merging/moving away from being “Debian” specific, e.g. 2 mailing lists, 2 IRC rooms, etc. : 3 green
  • How to make SLES join our party? (SLES = commercial SUSE)
  • set up / encourage adversarial public re-builders : 1 green
  • status of reproducing RPM (on Fedora?) : 2 green
  • what is the status and future plans for RPM packages? : 1 green

Encouraging upstreams 1

  • how could we encourage developers to write self-sustained test suites for sub-projects? *** green
  • how easy it is for a dev to make a project reproducible? * green
  • what to do with uncooperative upstream projects? *** green
  • feedback of reprod. to upstream
  • only contribute to master branch ** red
  • let other systems up on T.R-B.O * green

Encouraging upstreams 2

  • best practices for submitting patches upstream *** green
  • explore alternate solutions for lost metrics (as s/w becomes mirrored)
  • develop legal guidance for developers / distributors facing pressure to ship malware * green

Web apps :)

  • how do we verify reproducibility of web applications * green


  • is there a list of similarities / differences between operating systems reproducibility? * green
  • which could be better ways to distribute / check package signatures * green
  • how to securely and automatically sign packages/package lists
  • what to do with (not) reproducibly built software? ** green
  • testing reproducibility, integrating with
  • how can we make GitHub store immutable tarballs for tagged versions? (pristine tar?) * green
  • how can we make a database of signed build inputs and outputs
  • where should we collect reproducibility instructions / checksums of results?

Bootstrap 1

  • how acceptable is a not fully from source bootstrappable GCC
  • what do we call black boxes in bootstrap?
  • how far are we from diverse dual compilation?
  • find a way to bootstrap the Haskell compiler GHC without using a binary GHC. * green
  • find a complete bootstrap path for GCC. *** green
  • find a way to reduce the number of binaries we need to trust when building compilers. * green

Bootstrap 2

  • who wants to help: C compiler in Scheme, Scheme interpreter in simple assembly? * green
  • realize diverse-double compilation in the real world ** green
  • what does bootstrap “from source” mean?
  • what is a good bootstrap vs a bad bootstrap?


  • how to convince GCC to support BUILD_PATH_PREFIX_MAP? ** green
  • final specification for BUILD_MAP_PREFIX_MAP * green

Build environment

  • are Flatpak, Snapd etc the right way to build
  • how can we convince people that application bundles (like Docker images) are inferior to building software reproducibly? *** green
  • what are viable build environments for RB? (Docker, Vagrant, chroot…) * green
  • How do we handle other, sloppy package managers (like npm, etc)…? Import tools, mirror scripts? ** green
  • Is Bazel compatible with ReproBuild specs? (SOURCE_DATE_EPOCH, .buildinfo file…)
  • what should be done to make not only builds but system state reproducible?
  • why to use standardized build environments or not? * green