$ podman run --rm -it ubuntu:26.10
$ apt update -y; apt upgrade -y
$ rm --version
rm (uutils coreutils) 0.10.0
$ gnumkdir -p $(yes a/ | head -n $((32 * 1024)) | tr -d '\n')
$ rm -rf a
Segmentation fault (core dumped) rm -rf a
$ ls a
a
$ gnurm -rf a
$ ls a
ls: cannot access 'a': No such file or directoryThere's a whole load of basic bugs reported and ignored:
The fix is still sitting unmerged many months later.
This surprised me since I thought the project was in heavy bugfix/compat mode. I won’t touch it until I see some velocity on open bugs.
Only half joking.
To get a response on a buggy GNU coreutils patch of theirs [1], I had to mention it in a rust-coreutils bug months later...
[1] https://bugs.launchpad.net/ubuntu/+source/coreutils/+bug/215...
Maybe the bugs get traction if you have a service contract?
Best to file bugs directly to upstream, but that of course means you should try it on the latest upstream version and not whatever version ubuntu ships, so it's more friction.
It will die so just leave it alone.
I haven't tried chromium but I presume it's the same issue.
At work I'm forced to use ubuntu and I placed snapd on hold and added mozilla's own apt repository to my configuration to get firefox.
At least in the past few months the dbus crashes (been using systemd on debian for several years just fine, this never happened) that render the system unusable and un-rebootable have stopped… I guess when my company will decide to upgrade to 26.04 there will be more instability and problems.
Flatpak uses shared stable runtimes that are the same everywhere and don't take up space more than once. It also comes with a native update system and sandboxing. Snap is the same thing but worse.
IIRC Snap relies heavily on AppArmor for sandboxing, so on anything non-Ubuntu the sandboxing is non-existent.
8MB is pretty huge though; musl libc is famous for defaulting to much smaller per-thread stack size of 128KB (to avoid over-committing lots of memory when there are many threads - the main dev is really principled/opinionated on this topic, but again there are a few ways for applications to explicitly size their stacks as large as they need). Linux kernel threads get a bit less than 16KB!
[1] https://github.com/rust-lang/rust/issues/112788
[2] https://github.com/rust-lang/rust/issues/153827
By-default guaranteed tail calls really isn't rust's style, because it means subtle changes (introducing a destructor, re-ordering code, etc) can change semantics without you realizing it. If you want to guarantee that a call can't allocate a new stack frame you should have to say it.
But I can understand the preference for an explicit opt-in, to make clear that it is enforced and not assumed.
I'd argue that it's explicit - that's what a function call does and you don't have implicit function calls in rust.
> Seems the latter is a kind of compiler-level optimization, of which there are already many (I think) that change the semantics internally but guarantee the outward behavior stays the same.
What you're asking for here already exists. Tail calls might be optimized into not allocating extra stack frames, the rust compiler just doesn't guarantee that it will perform that optimization (and almost certainly won't when code is compiled without optimizations... for instance).
What people want is the semantic guarantee that the stack frame won't be allocated. Not just a compiler that often performs the optimization. Otherwise you can't be sure that your code will keep working with new compiler flags/versions/architectures/... You could say "whenever the code is the right shape we'll guarantee the optimization" (C++ famously did this for things like copy elision)... but now the shape of code comes with non-obvious semantic guarantees and that's not rust's style. Hence the proposal for a keyword instead.
No, it won't change semantics - if you say @musttail or similar, it will simply fail to compile if you, say, introduce a destructor - the semantics will not subtly change.
The whole idea of "let's change semantics to make it easier" is dumb.
If you want guaranteed tail calls, change your code until it works.
For recursion only kotlin.
(For most of these only with syntax specifying it)
Using recursion on unbounded inputs on a programming language that doesn't support that (which are most) is an extremely classical mistake that really should be known to all programmers, especially those of low level languages that care about safety.
Every time you call something recursively you should be thinking "how deep is this?".
Incidentally someone submitted a PR for this issue about 3 hours before the first comment about it in this thread - https://github.com/uutils/coreutils/pull/14554 (and 2 hours before this link was submitted to HN)
That's also not all that's happening. It's also making improvements like better internalization support, better error messages, and a small handful of other extensions.
Will this really make coreutils more secure? I doubt it, if anything there will be a river of new bugs.
So, again, why are they pushing Rust so much? Having Microsoft make Rust a 'Tier-1' language also doesn't bode well.
Microsoft making Rust tier 1 is great, it means probably one day we get a VS proper support instead of VSCode only.
If you head off to Microsoft official blogs, you will find out that Microsoft already has tier 1 support for Java (ironically), Python and Go, besides the usual .NET languages and C++.
https://bugs.launchpad.net/ubuntu/+source/build-essential/+b...
But it's clear that Ubuntu will remove coreutils, genuine sudo and other tools from the future versions. It's the direction, it's ideological and thus nor merit nor our feedback will change anything here.
That made me curious, it sounds related to this:
Ubuntu 26.04 Ends 46 Years of Silent sudo Passwords - 5 months ago (413 comments)
i was referring to their counterfeit sudo emulator written in rust. It's called "sudo-rs" afair.
Security issues discovered in sudo-rs - https://lists.debian.org/debian-security-announce/2025/msg00...
Sudo-Rs Affected by Multiple Security Vulnerabilities - https://www.phoronix.com/news/sudo-rs-security-ubuntu-25.10
Sudo-rs enables password feedback by default - https://www.phoronix.com/news/sudo-rs-password-feedback
It is frustrating that Canonical has no interest in fixing it, though. It makes it hard to take their claims seriously that you can still use GNU coreutils if you want.
Because even diving into it, I would agree with a prioritisation decision that puts this bug down the bottom of a priority list.
There have been a dozen CVEs reported against all of coreutils in the past twenty years. The most recent audit of uutils-coreutils turned up forty-four CVEs.
By all appearances they’re replacing battle-tested and fundamental tooling which hasn’t been a problem with extremely amateurish Rust. The threading highlighted in the linked post above seems pretty egregious.
Also for Rust based rewrites, they could start by bootstraping Rust compiler itself, dependent on C++ to start it.
They don't do it, because even though LLVM and GCC are written in C++, a pure Rust compiler would not scale to the same level of contributions, and existing capabilities.
I would appreciate Go much more otherwise.
You weren't kidding: it was exactly 4 years ago ("September 13, 2022").
https://github.com/trifectatechfoundation/sudo-rs#difference...
One systemd patch at a time.
Ubuntu does offer some certifications but only for paying customers, so everyone else should really steer clear.
My source is this interview with the VP of Engineering at Canonical on this topic: https://corrode.dev/podcast/s05e05-canonical/
We might see a fracture open slowly. For me, even AGPL is not enough
There is a reason all FOSS OS alternatives for embedded systems like Zephyr, NuttX, FreeRTOS, IDF, Arduino,... are not GPL based, while Google has purged Android and ChromeOS from it, with the Linux kernel being the only GPL piece left.
They worked pretty fine for decades, now, who needs these rewrites? Not saying it's useless, but in practice, what benefits did this bring?
Just because it is Rust, it is not safe!
It worked before, don't replace it!
etc.
I had to reimplement and reverse engineer old tech myself as part of my dayjob and had those engineers seen my results it probably would have improved their work as well, since I usually found oddities that they probably did not intend to be that way. This means my work on their work could be seen as another pair of eyeballs, bullet-proofing their original work, instead of seeing me as a threat. That additional pair of eyeballs is crucial to open source software.
This is why it is sad that too much about this whole discussion feels like yet another culture war, heated on the stove of social media figures looking to convert heat into ad revenue.
Which is why I would love to have more concrete points of technical criticism of specific bits maybe even to specific lines in the code or specific reproducable behavior.
If we go the culture-war route nobody wins, if we discuss both solutions on their merits, we all can win.
You can split hairs however you want, but this created a legacy, and is why Ubuntu is still one of the top recommended distributions for beginners.
And they are slightly behind RHEL: https://commandlinux.com/statistics/linux-server-market-shar...
FWIW, Canonical did not reach out to any of us who maintain GNU coreutils before, after, or during the transition. Had we known, we could have easily warned them about the incompatibilities.
They have forced systemd despite feedback and genuine concerns.
They have forced fake sudo and uutils the same way.
So, ideology over merit. That doesn't mean that all of the Ubuntu devs are this way, but this means that the company is consistent in its ways to hurt Linux.
Canonical is a company they do what the CEO wants. And you are free to do what you want.
Quick question: are the fruits of your labor mostly given away for free?
Did you mean nothing "but" good?
The other comments are about as good as the one you replied to.
[0] https://discourse.ubuntu.com/t/the-future-of-ai-in-ubuntu/81...
If it goes really sideways, and it may, you can either fork Linux or move away to something like one of the BSDs.
Each piece that becomes MIT means less pressure on corporate users to give back any changes they make, and we'll end back up in the 1980s again where "Amazon Linux" is full of secret-sauce they refuse to publish and makes the base system incompatible with "Google Linux" (or whatever happens to be kicking about), creating deliberate lock-in out of a system that started open. In much the same way that macOS and FreeBSD are divergent today.
That would be an awfully awkward move in the realm of Linux-related politics but if having an MIT-licensed coreutils was such an existential thread, at least you can fix it with aggressive license moves and not code.
I am not totally sure I see the actual concern here, that a company is going to sell devices with a really great `find` implementation but not contribute it upstream?
What it meant was a headache for writing platform-agnostic software. It was not a productive way to create software.
Replacing GPL software with MIT software just encourages this behaviour to come back. We already see it with how macOS userland took FreeBSD and sprinkled incompatibilities everywhere.
2) Seeing how bad the Linux kernel is with all the AI CVEs. It will get worse.
BSD is the future.
Also Wayland is it being forced on us? I have plenty of coworkers that run X daily because they are still afraid of the Wayland boogeyman despite the fact that their supposed clipboard and screen sharing problems in Wayland (the only two supposed problems they can name) have been solved for years.
Ss for AI slop. There is lots, but I do not think Linus will tolerate a heavy quality degradation and policies will be set up to strike a good balance.
There were forty-four against this project in just the last audit.
I am all for RIIR in cases where it makes sense. This does not even remotely appear to be one of them. By all appearances the quality of the code is extremely amateurish at best. coreutils has not been a significant source of vulnerabilities in the past, and they’re replacing it with code written by amateurs that performs worse and already has a worse security track record.
Was there an audit against coreutils? If not, it's not really apple-to-apple comparison.
We are talking about fourfold more CVEs over a twentyfold reduction in time.
Absent more information the default should be to hand wave it away as probably such a difference. CVE counts are not a even slightly reliable metric.
Other ones I find concerning are that you could also bypass '-- no-preserve-root' with a symbolic link to root [2]. Or by using paths equivalent to "/", e.g., "/../" [3]. Historically, GNU coreutils has been pretty good with symbolic links and avoiding TOCTOU races. The only notable one I can remember is a chmod(1) bug [4].
I agree with your general point that the number of CVEs is a useless metric, though.
[1] https://nvd.nist.gov/vuln/detail/cve-2026-35352 [2] https://nvd.nist.gov/vuln/detail/cve-2026-35349 [3] https://nvd.nist.gov/vuln/detail/cve-2026-35338 [4] https://github.com/coreutils/coreutils/commit/425b8a2f534fe0...
[0]: https://fil-c.org/.
[1]: https://bannalia.blogspot.com/2025/11/comparing-run-time-per...
* Guaranteed to crash rather than potentially grant arbitrary code execution.