Dirkjan Ochtman: writing

Rust 2019: Ownership without fear

Published on 2019-01-01 by Dirkjan Ochtman in tech, code, rust

Like last year, the Rust community team asked community members to write blog posts "proposing goals and directions for 2019"; this is mine. Like withoutboats' post and Niko Matsakis' take, this post will focus on organizational issues. As such, the "ownership" from the title refers to a leadership principle, not the technical type system concept we all know and love.

Finance without fear

I believe the Rust project must figure out how accept donations for the benefit of the Rust language, compiler and ecosystem. Whether this involves a new legal entity or not, we should use the corporate money on the table where it could enable the community to move the ecosystem faster than otherwise possible.

Even if other communities have run into trouble with this, the focus of the Rust project on positive-sum outcomes and careful involvement with the community should make it possible to come up with proposals that are widely supported. Things like improving the state or scope of CI, having a procedural macro book written or even building custom tooling might all be good ideas.

So far, the Rust project has preferred existing tools over building our own. However, I think we run into the limitations of this strategy both in the example of CI and in the limitations of GitHub issues for some of the more involved discussions. This is a classic build vs buy discussion -- if we consider CI and RFC discussions to be a "core business" of the Rust project, then it might make sense to invest in improving these parts of the project's process.

(Is "tooling without terror" too terrible a pun?)

Foundation without fear

Setting up a legal entity and governance structure for the Rust project appears to be a controversial topic in the Rust community. Of course, it could be a home within an existing foundation: joining Thunderbird under the umbrella of the Mozilla Foundation, or another entity like the Software Freedom Conservancy. I would like the increased transparency and accountability that might come with a more explicit setup where it concerns how the leadership of the project evolves.

Since it keeps coming up, it would be good to have an RFC about the foundation idea; to have a thorough conversation on the benefits and downsides. If the latter end up outweighing the former, the RFC can serve as negative space documentation (per Graydon) for everyone thinking about it.

In a different vein, I think PEP 8016 is worth exploring as a carefully considered alternative we could crib ideas from. As an experiment, we could have part of the core team be elected by a (large cross-section of) the community.

Asynchronous alignment

I think the Rust project could benefit from an increased sense of the direction of the project. While the language design and library evolution processes "just" some adjustments to the increased scale at which we're operating, other parts of how the project executes are not so well-defined, or happen in synchronous meetings that are opaque to the community. I'm used to open source projects where decision making happens exclusively in asynchronous venues, and the current way Rust teams and working groups function is quite different -- with a notable exception for the way the compiler team documents their work.

The yearly roadmap building effort is one great way of doing this, but the yearly cycle makes it a very coarse-grained check-in. One suggestion I've been thinking about is to have a community event (maybe with video?) every release cycle or two where a group of core team members answers crowd-sourced questions from the community (along the lines of an AMA or Google's TGIF event).

This could also help cut down on the "Why don't you just" and "Be Heard" sentiments that I've seen core project team members lament over the past year. I think those sentiments come from a feeling of powerlessness and being underinformed. In my mind, more deliberate and continuous communication about the state of the project could go a long way towards improving on this.

Careful conduct

Although I wholly support the code of conduct and appreciate many aspects of the way we interact online, there's some things that I think could be improved. While I've seen people expressing their personal frustration with a project decision get quickly moderated, I've also seen users who keep posting vague forum threads or exert significant stop energy on others' proposals. I wish we could be more openly critical of decisions (not people) while at the same time more strict towards net-negative participants.

On a more subtle note, I've felt that core project team members cast the community as an angry mob at times. Although I realize it is a big job, I think it's fair to ask project leaders to bring more empathy to the table in these cases -- to me, that is an important part of leadership. If a significant part of the community is up in arms about something, there likely is a kernel of truth to their argument, and the leadership should respond to the sentiment to prevent it from festering.

Update: interesting discussion on these topics on Reddit.

Taking the long view

To my taste, too much focus in 2018 was spent on releasing the edition. We could have spent more time addressing technical and organizational debt and released the edition 3 or 6 months later to little consequence. The Rust release process has been carefully engineered to optimize for cautious movement towards long-term goals -- and the edition process, in setting a fixed scope and an arbitrary hard deadline, subverted a number of these goals. This caused issues around the release of the website as well as problems with tools when 1.31 was released.

On the one hand, the cautious, deliberate approach to language design and compiler development have served us well, and will likely continue to do so. However, we should not forget that this process functions well in part due to an imposed feedback cycle that gives enough time and space for people to experiment before casting the new feature in (stable) stone per Hyrum's law. In a similar vein, we cannot expect to get our organizational changes right on the first try, and so we should not be afraid to experiment and iterate with the way the community works on the Rust project, rather than taking a long time to get it just right. This is especially true because the experiment period allows a wider community to participate and interact with the proposed change, thus reinforcing community alignment and improving feedback.

In this sense, we might learn from Jeff Bezos when he talks about a bias to action, saying that we should not spend too much time discussing decisions that are easy to change after the fact. For Rust, too, we want to remain at Day 1 for as long as we can -- let's remember the "without stagnation" part.

Contemplating Cargo

On a somewhat more technical note, I hope for more attention given to Cargo. While Cargo is a great tool in many ways, it also suffers from a number of usability cliffs where the behavior is hard to predict or understand. When I tried to contribute, I found that there's also a decent amount of technical debt, and my attempts to improve this through refactoring were met with such reluctance that I stopped contributing. From recent reports, it seems I'm not the only one.

Since Cargo is so central to the Rust experience, I think we should not undervalue it; as one example, the interactions between Cargo and rustc also influence the perception of those compile times people keep talking about. I was very happy to see the leadership changes and increase of the team's size, and I hope those changes will lead to further Cargo improvements this year.

Unused inventory, redux

Last year, I wrote at some length about the concept of unused inventory. This is still very much on my mind, and I was happy to see Niko talk about it in very similar terms. I hope we can improve things here.

Closing thoughts

I'm still as bullish on the Rust language as ever. Non-lexical lifetimes and the module system changes have made an already great language even better, async/await is going to be great. What I most want from Rust, though, is that more of the software in my life can enjoy its reliability and efficiency (in performance vs footprint), and for that we need adoption and sustainability. While the technical side of the project is working well, I've been concerned about the functioning of the project's governance and processes. A number of Rust 2019 posts have addressed similar concerns, which makes me hopeful for 2019.

Patreon update #2

A little over 2 months ago I started a Patreon page to see if I could gain some financial support for my open source work (with the goal of doing more such work). I posted an update on Patreon after 10 days to talk about what I had been up to, so I figured it was time for an update. Instead of posting it to Patreon, I'm posting these updates to my blog from now on; this gives me full control over the posts and will hopefully boost the update frequency of the blog a little bit.


Askama is the type-safe Jinja-like Rust template engine I created. Askama 0.7.1 was released in on July 23rd with the following improvements:

Since that release, botika has contributed a few fixes around nested macro scopes (possibly a regression from 0.6), which I will release soon.


Although Quinn (my nascent QUIC implementation in Rust) saw little progress in code over the past two months, I still have good hopes for the future. I talked to Benjamin Saunders about merging his quicr implementation with Quinn, and it looks like we will move forward with that. For now we'll likely keep the Quinn name, but start from Benjamin's code base. Since building and maintaining a QUIC implementation is a lot of work it probably doesn't make much sense to have two, and I think merging these projects is for the best.


  • Updated the Rust ebuilds to 1.27.0 and 1.28.0. As discussed in the previous update, these versions now allow installing the cargo, rustfmt and rls components as built by the Rust build system (or the binaries in the case of rust-bin). As upstream makes the distribution more monolithic, this will make it easier to get updates into the Gentoo repository.
  • Introduced a new virtual/cargo ebuild to abstract over the cargo builds installed by dev-lang/rust, dev-lang/rust-bin, and dev-util/cargo.
  • Updated the CouchDB ebuild to 1.7.2 after a vulnerability was reported in 1.7.1. This was the last CouchDB release in the 1.x range, and since another vulnerability was disclosed, 1.7.2 is known to be vulnerable. I have been dissatisfied with the direction of the project, so I've finally removed myself as a Gentoo CouchDB maintainer. No one has stepped up, so I'll start the process for having CouchDB removed from the Gentoo repository soon.
  • Updated the ripgrep ebuild to 0.9.


In June, I released a tiny Python library called abna that will log into the Dutch ABN Amro bank's web interface and download your transactions for you. I forgot to mention it in the previous update, so will expand on it a little.

It's been a long-standing annoyance for me that automating this process was impossible. For a long time, the web interface used a hardware token which relies on debit card access and punching in your PIN code. However, in recent years they've added a five-digit so-called soft token that enables limited access to the account, including seeing past account mutations. In June, I decided to reverse engineer their login process and figured out the code to support it (spoiler alert: it involves some RSA encryption).

In July, there was a nice PR from Ivan Vasić to allow downloading the mutations for another account than the login account, which I promptly merged and released as 0.2 after improving the packaging situation a little more.

Assorted other work

Many thanks to my patrons; I hope this is worthy of your support.

Science fiction recommendations

Published on 2018-07-15 by Dirkjan Ochtman in books

I've been thinking about writing more blog posts again recently. Since I sometimes write in blog-like form elsewhere, I thought I might syndicate those posts here, partly out of a desire to make it easier to find things I've written (compared to digging through my Twitter feed for links). As such, here's an edited Hacker News comment from a post asking for SF recommendations.

Isaac Asimov is one of the classics. I'm particularly fond of the robot novels (all four of the Elijah Baley ones especially) and the entire Foundation series. Of course, you also can't miss the robot short stories. The End of Eternity is less famous, but it was one of the first ones I read and classic time travel fiction.

At some point I found Charles Stross' Accelerando online, where it is freely available along with a bunch of other stories, and found everything I've read enjoyably fast-paced. In particular the Laundry series — though arguably these cross over from SF into fantasy a bit — and the Halting State trilogy. (In recent years, I've bought every Laundry book as soon as it came out.)

In terms of online available work, Cory Doctorow's work is also great. Like Stross, his work is more near-term SF, which I like. It often moves fast and is politically interesting; sometimes the activism shines through a little too much, but on the plus side it makes me think. His latest is Walkaway, which I would recommend.

I got into Neal Stephenson through Cryptonomicon, which is awesome and a little crazy. Stephenson has a rambly wordy style, but that lends a kind of depth to his stories — and some of his books make me laugh out loud (including Cryptonomicon) which is rare for me. After that, I got into Anathem, Reamde and Seveneves, all of which are big and interesting and great reads (Anathem has a slow start, but it's worth it). I tried one of the more historic ones (I think it was Quicksilver) at some point but haven't finished it. His latest work The Rise and Fall of D.O.D.O. is lighter, but another fun take at the time travel theme.

I would also recommend William Gibson. I read the Sprawl trilogy a long time ago, and it's made a lasting expression — I started re-reading it recently. I also liked the Blue Ant trilogy and The Peripheral, but have so far missed the more recent work (which means I have something to look forward to).

In the one-off category: The Sparrow by Mary Doria Russell is one of my all-time favorites, and mixes deep SF with psychology and religion in interesting ways. There's a sequel, but it's not as good. I also liked The Time Traveller's Wife by Audrey Niffenegger, which is also on the softer side. I read John Scalzi's Redshirts and liked it (though probably not as much fun if you're not familiar with the Star Trek universe). It feels similar to Ernest Cline's Ready Player One in some ways. Daniel Suarez's Daemon is fun and easy to digest and has some interesting ideas, as does its sequel, Freedom. I liked Robert J. Sawyer's The Terminal Experiment, but someone I recommended it too found it too flimsy — I still think it's fun, if not very deep. I also bought his Factoring Humanity and liked it okay.

I hope this list is useful to someone. If you have recommendations for me based on this selection, I'd like to hear them.

Rust in 2018

Published on 2018-01-14 by Dirkjan Ochtman in tech, code, rust

In a call for blog posts, the Rust community team asked community members to write up their vision for what the Rust community should focus on this year. I've wanted to contribute my thoughts and have been thinking about what to write ever since. I've been able to benefit from the many people who already posted their thoughts to sharpen my own thinking. I came up with 5 categories:

  1. Unused inventory
  2. Meta-ergonomics
  3. Deep docs
  4. Web development
  5. Paper cuts

In rough priority order, these range from high level community and product thinking to technical things that I'd like to see. Let's dive in.

Unused inventory

Avery Pennarun recently wrote an essay called An epic treatise on scheduling, bug tracking and triage; it's long, but if you're interested in software engineering process, I think it'll be worth your time. One of the points that really stuck with me is where he talks about unreleased software as inventory.

Avery discusses how Kanban was invented in the Japanese car industry, where minimizing inventory was one of the driving factors. As Avery explains, this very much applies to shipping software: unreleased code means you have spent the time to design and implement the feature, but now you have to pay for maintenance of this code (in terms of complexity in implementing other bugs or features) without realizing the value of shipping the actual feature to your customers. And that's not even discussing the opportunity costs of how you could have spent the time spent on unreleased feature A to ship released feature B sooner, increasing the value brought to your customers.

If you doubt the analogy, please go and read Avery's essay, since I cannot do it justice here. My point is this: rustc has a lot of unused inventory.

So I found myself agreeing with Nick Cameron's Rust 2018 post, where he describes his wish for 2018 to be "boring", because we should just finish up what we've got in the pipeline instead of starting new things. Pascal Hertleif's take on Rust 2018 is even stronger, calling for consolidation and rapidly reducing the number of in-flight unstable features. Currently there are 113 in the language and 155 in the library; see also my analysis of open library tracking issues.

If you think about that in terms of unused inventory: how much time has the community spent on designing and implementing these features? How much value, in return, has made it into the stable Rust compiler that most people use? How much time has been spent on maintaining these features while we were shipping other things? How many of the commits going into the master branch during any given release cycle actually affect stable Rust users' life six weeks later? When is an unstable feature actually used so much that it has effectively prematurely stabilized? For example, if there is agreement that the design can be improved, are we still willing to break the codegen features Rocket uses?

One challenge here is that Rust is an open source community, not a hierarchically-driven top-down organization where the leaders can just tell people what to do. Still, if the community can come together and agree on priorities, we can focus more on shipping features in stable Rust. We could adopt a rule that features cannot stay in nightly if no progress on stabilization is being made for more than 4 cycles. Or agree as a community that no more than 25 language and 25 library features can be in-flight at any time.

My other conclusion is that stabilizing features is a bottleneck in our factory for shipping Rust. So while we work on reducing inventory, we should at the same time try to increase the capacity of bottlenecks in the stabilization process.


I've been thinking about metacognition recently as a nice word for a useful concept. Similar to how metacognition means the awareness and analysis of one's own learning or thinking processes, and playing off of the 2017 year theme of ergonomics, maybe 2018 should be the year of going meta: meta-ergonomics, where we focus on the process of improving language ergonomics.

In order to scale the number of people that can help design, implement and stabilize new features and fix bugs, how can we best connect the high-level goals to the lower-level implementation process? Can we highlight the current blockers and accessible "good first bugs" where mentoring is available?

I subscribed to some issues in the GitHub roadmap issue tracker last year, but did not find myself deriving a lot of value over the course of the year. There were good write-ups of what needed to get done, but few updates over time and little connection to the ongoing implementation effort. The best way I've found to keep track of the non-lexical lifetime effort, for example, was just to check out links from This Week in Rust, which mostly talked about stuff that was completed rather than upcoming opportunities for contribution.

One important part has already been kicked off by Niko Matsakis: the Rust Compiler Book will hopefully become an important resource this year for helping people hack on the compiler. When I tried my hands at one small language feature this year, documentation like that was sorely lacking.

Deep docs

As with missing documentation for the compiler, the other area where Rust can improve next year is documentation. While The Rust Programming Language is a great resource for people just starting with Rust, I ran into a number of cases where it didn't fulfill my needs and I had to ask around for help.

The community is wonderful in providing such help, but at the same time it felt frustrating when there was no documentation to better describe the language's syntax and semantics: what edge cases are allowed or not, what parts remain unimplemented, why certain restrictions are there and what relevant RFCs are in the pipeline. I'm not sure whether this is intermediate-level documentation or reference documentation, or maybe those really are the same thing.

Web development

The big ticket item here is WebAssembly. I believe that WebAssembly is about to take off in a big way, particularly once it gets access to DOM APIs. My personal end goal here is to be able to write web apps where both the backend and the frontend are written in Rust. Ideally, the UI would leverage functional reactive programming (see Yew), so that the app's state lives on the client and the server just ships state updates as required. (Elm, but in a rustic way.) Lots of progress was made with WASM support in 2017, but making that really polished would make Rust a top contender for greenfield WASM projects (that is, not using legacy C/C++), which seems like an important use case going forward.

Even if you just want to write Rust on the backend, the infrastructure is still maturing. Rocket has many cool ideas, but only works on nightly and doesn't yet support asynchronous programming. Gotham seems to be the next viable option, on stable and with support for futures, but it seems to be in the very early stages (starting with the documentation). For simpler API services, it looks like hyper (hopefully soon with built-in HTTP 2 support) and serde work well together, although something with more polish and less boilerplate would be nice.

So far Askama, my take on templating for Rust, hasn't taken off in a big way (although I've been very happy with contributions!). I'm not sure why exactly; I'll keep iterating as I haven't seen any competition that makes more sense to me. I would like to explore how it can fit in with functional reactive programming -- if that ends up working out, it may also draw more people in.

In general, it doesn't feel like Rust is web yet, so I hope this will improve in 2018.

Paper cuts

And then there's a list of things I've ran into over time that I'd like to see some traction on somehow. Note that I do pretty much all of my development on stable Rust, and that contributes to some of these problems.

  • When I tried to expose a parser result for imap-proto, I was surprised to find out you cannot access enum variants through type aliases. I wrote up a pre-RFC to help fix that; stabilizing that in 2018 seems like a challenge.
  • In one case I wanted to use Vec::resize_default(), which has been waiting for stabilization for about 8 months now without any signs of progress.
  • Installing clippy or rustfmt (as a stable user) and keeping them running takes hard work and troubleshooting time. Updating these tools means I have to update nightly, and the other way around. On the latest update, rustup warned me I should delete the separate installations to allow it to install the rustup-managed ones, but that actually didn't work.
  • Writing a Tokio network protocol client (tokio-imap) took a lot of time, since the documentation focused much more on writing servers at the time. It feels like Tokio made little progress in 2017; I hope 2018 will be better.
  • The ergonomics around futures are not where they should be. I hope impl Trait and async/await can make enough progress in 2018 to make this better.


I deeply believe in Rust; I've been trying to articulate that in another blog post (still in progress). I hope 2018 will be another great year for Rust, and I am eager to participate more in the Rust community over the coming year.

Rust is a big tent

Published on 2017-05-19 by Dirkjan Ochtman in tech, code, rust

Cue images of fireflower-decorated tents.

Over the last year, Rust has replaced Python as my favorite programming language. Recently, the Rust community celebrated the second birthday of Rust 1.0, and the birthday blog post mentioned that 438 people contributed for the first time to the compiler and standard library this year.

This led me to wonder how this compares to other modern programming languages. Specifically, I was wondering about Go and Swift, languages that are of similar vintage and that compete in the same space of compiled, statically-typed languages with a performance focus.

One of the concerns I have seen from people about Rust's viability is the size of its community -- can Mozilla and volunteer contributors evolve Rust at a fast enough pace? And how does that pace compare to these other languages, both of which are backed by large corporations?

So I pulled Git repositories for each of these three projects and graphed the number of non-merge commits in each of the repositories from the first day:

Commits over time

Then, I also graphed the cumulative number of unique authors:

Commits over time

Code and data can be found on GitHub. I manually culled the first 4 commits from the Go repository, which reported being from 1972, 1974 and 1988; the first commit that I kept is from March 2, 2008. Swift started on July 17, 2010 and Rust on June 16 of the same year, surprisingly close to each other.

Clearly, this is a crude analysis (even ignoring the Excel charts). Repositories may not all contain the same depth of components (like compiler, standard library, documentation), and commit sizes could substantially differ due to differing project cultures. Still, two broad patterns are apparent:

  • Rust has way more unique contributors than the other languages
  • Rust gets many more commits than Go, but Swift is moving faster

As a result, I'm confirmed in my optimism about Rust's future.