rpm-ostree VS cxx

I definitely agree that immutability offers considerable value in regards to improving security. But arguably it's insufficient to pull the win over mutable Fedora due to the losses caused by the inability to install the kernel-hardened package and the lack of UKI (Unified Kernel Image) support.

Issue: https://github.com/coreos/rpm-ostree/issues/3944

Oversimplifying might have been the most sensible in this context. However, you might have gone a little bit too far as your description fits only NixOS, Guix and distros that utilize rpm-ostree.

here's the documentation of ostree (the package manager)

Now... this was VERY alarming to say the least, so I went online and did indeed find an issue on GitHub.

And there are still some issues with layering. Some packages that don't behave or follow standards will modify files in /usr/local, which isn't supported, so you simply won't be able to install them on Silverblue. I think it's the same for /opt as well. (https://github.com/coreos/rpm-ostree/issues/233) This means it fundamentally can't do everything Workstation can, which is unfortunate.

ublue is based off of fedora and rpm-ostree, which is what "CoreOS" is today.

What happened was old school CoreOS was A/B partition based: https://github.com/coreos/docs/blob/master/os/sdk-disk-parti...

My memory is hazy but here's how I remember it: After Red Hat acquired CoreOS they rebased the entire thing around rpm-ostree, which is the CoreOS people know today: https://coreos.github.io/rpm-ostree/

At the time there was some anxiety in the community as to what would happen, as there was no direct upgrade path from old CoreOS to new CoreOS. Theoretically if we all believed the kool-aid we were drinking it's just a redeploy, no pets!

Kinvolk came along, forked it, and made Flatcar Linux, which kept the A/B partitioning system, and more crucially, let you just change a config file and all your old CoreOS nodes would just move to Flatcar and then you were good to go. So now if you wanted to stay on the system you were comfortable with you could just use Flatcar. If the composability of rpm-ostree attracted you then new CoreOS have you covered. Red Hat deserves a hat tip here because in their documentation/blog they explicitly mentioned Flatcar as an option for people who wanted to stick with what they know, which I thought was cool and how I discovered it!

Later on Microsoft acquired Kinvolk and and then people raised eyebrows. I have not checked in a while but the folks involved continued to do their thing and run it like a good OSS project, hold public meetings, all that stuff.

I use both and they're both high quality.

Whenever I was looking at using CoreOS, I was somewhat disheartened that automatic reboots weren't built in: https://github.com/coreos/rpm-ostree/issues/2831. Has this changed? I know zincati has maintenance window support, which would also be nice to have.

Doesn't look like it https://github.com/coreos/rpm-ostree/issues/1091

There are cxx and autocxx, what else do you propose to do?

I would like to see a comparison of how this compares to Rust. In terms of interoperability it has Cxx (https://cxx.rs) to offer safe bindings to C++ but also has great support for Android, Linux and many other systems. You don't even need to hack together Windows bindings (as explained in the blog post) because Microsoft offers official bindings (https://crates.io/crates/windows). I'm not sure if I'd call it a superpower if any potential interoperability has to be written to be used (compared to it already being available). Or rather, in comparison to what is interoperability a Swift superpower? Certainly not C++ or C which can be used in a far wider set of targets.

We selected Qt as a cross-platform solution. The C++/Rust interface is the clunkiest and ugliest part of the application, and rather complex because some state is shared between several windows in the GUI and several threads in the backend, and any component might modify that state at any time, and updates have to be transmitted to the other components without introducing inconsistencies. Using cxx [1] helped a little, though.

The project began in 2020, and I'm not sure what I'd choose as a GUI framework today – definitely not Qt Widgets, though.

[1] https://cxx.rs/

If the build process for the C library isn't too involved I recommend using cxx bridge (https://cxx.rs/) and letting cargo handle the build and linking. cxx basically allows you to describe the bidirectional interface (although it sounds like you only need 1 direction, which is fine too) in Rust code and it provides a "good enough" API for compiling C code inside the build.rs file.

The tooling for the first kind -- calling Rust from another language -- is a bit less developed, and tends to rely on code generation that doesn't necessarily produce a natural C API. cbindgen, uniffi, cxx, and Diplomat all take this course.

I would like to utilize OMPL's functionality in Rust code, so I want to call into OMPL C++ code somehow in Rust. I've seen two (non-mutually-exclusive) options so far: - rust-cpp, which allows you to write C++ code in Rust within the cpp!() macro. - cxx, which allows you to define both sides of the FFI boundary manually (as opposed to bindgen's automatic generation).

I'm not sure how to do this in cxx; issues like https://github.com/dtolnay/cxx/issues/447 suggest that this isn't settled yet?

I use non-vendored dependencies for the Buck build in https://github.com/dtolnay/cxx.

There's also the cpp and cxx crates for doing C++/Rust interop, but they probably aren't appropriate to use in all cases. The C ABI is definitely the safest way to go unless you're really trying to marry Rust and C++ code bases, not just writing library bindings.

There's also cxx (can't vouch for it personally but it claims to make things a lot easier) https://github.com/dtolnay/cxx