mmsd VS stable_deref_trait

> MMS or Multimedia Messages are supported by gammu but they are stored in a binary format I have yet to find documentation on how to make something usable out of it for download. Any info in it is greatly appreciated.

You could look at this implementation: mmsd-tng [1]. It is used to handle MMSes on the PinePhone for instance.

[1] https://gitlab.com/kop316/mmsd/

I installed mmsd-tng from Chris Talbot's repo (I don't run Mobian unstable and didn't wanna go fetch the package from there), and installed Chatty from Purism's repo per the Mobian docs. To be sure of no conflicts, I carefully uninstalled the existing Chatty via dpkg -r --force-deps chatty to remove just Chatty without taking Phosh out with it.

Apparently MMS isn't used much outside of North America so it's not as high of a priority. I' on Mobian and use Janky MMS to at least receive them, but I still can't send them. There is also an MMS daemon that someone created to at least process them, but getting a messaging app to pick them up is still a challenge. They are also working on getting it integrated into Chatty. Apparently its getting pretty close but its kind of slow going because its mostly one guy working on it. So if you're any good with C (especially UI design) they are always open for more contributors.

To get it working, you basically need a fork of mmsd (i.e. mmsd-tng) and you need an app that can pull the MMS messages in. The same developer who has worked on mmsd (kop316) has spent a good amount of time updating Chatty/Chats with his own custom branch, though it is quite barebones and really only allows receiving MMS images as file:// links in the UX. It sounds like Purism will eventually get around to implementing this in the UX but it may not be for months.

To elaborate, there is a recurring trend of sound C programs turning into unsound Rust programs, because shared mutability is often necessary but Stacked Borrows places strict conditions on constructing &mut T (they invalidate some but not all aliasing *const T), and it's less ergonomic to work solely in raw pointers and avoid creating Box or long-lasting &mut T (or for intrusive collections, any &mut T at all).

For example, matklad (the author of rust-analyzer, one of the preeminent Rust programmers and someone I'd expect to get code right) made a recent blog post on "Caches In Rust" (https://matklad.github.io/2022/06/11/caches-in-rust.html). The cache is built around https://docs.rs/elsa, which is built around https://docs.rs/stable_deref_trait/latest/stable_deref_trait..., which is unsound for Box and violates stacked borrows in its current form (https://github.com/Storyyeller/stable_deref_trait/issues/15). However, the rules may be relaxed or more ergonomic alternatives added (https://github.com/rust-lang/unsafe-code-guidelines/issues/3...), it's uncertain right now.

(Also I go by "they".)

Unsafe Rust is an esoteric language without iron-clad guarantees, and type-level programming and async Rust is an esoteric metalanguage (https://hirrolot.github.io/posts/rust-is-hard-or-the-misery-...). For example, matklad made a recent blog post on "Caches In Rust" (https://matklad.github.io/2022/06/11/caches-in-rust.html). The cache is built around https://docs.rs/elsa, which is built around https://docs.rs/stable_deref_trait/latest/stable_deref_trait..., which is unsound for Box and violates stacked borrows: https://github.com/Storyyeller/stable_deref_trait/issues/15

There is a recurring trend of sound C programs turning into unsound Rust programs, because shared mutability is often necessary but it's difficult to avoid creating &mut, and Stacked Borrows places strict conditions on constructing &mut T (they invalidate some but not all aliasing *const T).

The cache is built around https://docs.rs/elsa, which is built around https://docs.rs/stable_deref_trait/latest/stable_deref_trait/trait.StableDeref.html, which is unsound for Box and violates stacked borrows: https://github.com/Storyyeller/stable_deref_trait/issues/15

StableDeref has multiple issues under the current Stacked Borrows model: https://github.com/Storyyeller/stable_deref_trait/issues/15