Even before the Bcachefs file-system driver was accepted into the mainline kernel, Debian for the past five years has offered a "bcachefs-tools" package to provide the user-space programs to this copy-on-write file-system. It was simple at first when it was simple C code but since the Bcachefs tools transitioned to Rust, it's become an unmaintainable mess for stable-minded distribution vendors. As such the bcachefs-tools package has now been orphaned by Debian.
From John Carter's blog, Orphaning bcachefs-tools in Debian:
"So, back in April the Rust dependencies for bcachefs-tools in Debian didn’t at all match the build requirements. I got some help from the Rust team who says that the common practice is to relax the dependencies of Rust software so that it builds in Debian. So errno, which needed the exact version 0.2, was relaxed so that it could build with version 0.4 in Debian, udev 0.7 was relaxed for 0.8 in Debian, memoffset from 0.8.5 to 0.6.5, paste from 1.0.11 to 1.08 and bindgen from 0.69.9 to 0.66.
I found this a bit disturbing, but it seems that some Rust people have lots of confidence that if something builds, it will run fine. And at least it did build, and the resulting binaries did work, although I’m personally still not very comfortable or confident about this approach (perhaps that might change as I learn more about Rust).
With that in mind, at this point you may wonder how any distribution could sanely package this. The problem is that they can’t. Fedora and other distributions with stable releases take a similar approach to what we’ve done in Debian, while distributions with much more relaxed policies (like Arch) include all the dependencies as they are vendored upstream."
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With this in mind (not even considering some hostile emails that I recently received from the upstream developer or his public rants on lkml and reddit), I decided to remove bcachefs-tools from Debian completely. Although after discussing this with another DD, I was convinced to orphan it instead, which I have now done.
ELI5: What the fuck is going on with Rust in Linux?
On the kernel side, there are disagreements between long term C maintainers (who may not know Rust or may actively dislike it) and the new Rust community trying to build in Rust support. To make the Rust parts work, there needs to be good communication and cooperation between them to ensure that the Rust stuff doesn't break.
On the Debian side, they have strict policies that conflict with how Rust development works. Rust has a dependency system called Cargo which hosts dependencies for Rust projects. This is different from C, C++ where there really isn't a centralized build system or dependency hoster, you actually install a lot of dependencies for these languages from your distro's repos. So if your Rust app is built against up to date libraries in Cargo, it's going to be difficult to package those apps in Debian when they ship stable, out of date libraries since Debian's policies don't like the idea of using outside dependencies from Cargo.
As they should. You don't just auto-update every package to bleeding edge in a stable OS, and security goes out the window when you're trusting a third-party's third-party to monitor for dependency chain attacks (which they aren't). This is how we get Crowdstrike global outages and Node.JS bitcoin miner injections.
If some Rust tool is a critical part of the toolchain, they better be testing this shit against a wide array of dependency versions, and plan for a much older baseline. If not, then they don't get to play ball with the big Linux distros.
Debian is 100% in the right here, and I hope they continue hammering their standards into people.