Aria Desires

this is a followup on #149 cc @RalfJung: welcome to round 2, fight me

Extremely Rough Note before I wander off: I feel like I want to define a concrete notion of two different ways a type can occupy memory to address how unions/enums...

hmm yea, i think the new borrowchecker and/or some new sugar was added since this section was written which makes this not actually a good example anymore. Will have to...

In order for the Rust project to take advantage of this, it would need to be based on the `rust` branch, which has diverged from master in incompatible ways.

Part of me wants to take a go at arguing that technically trait objects have no subtyping relationship, even if their traits have a subtyping relationship, but honestly just pointing...

I was considering proposing adding some alternatives to [Backtrace::frames](https://docs.rs/backtrace/0.3.67/backtrace/struct.Backtrace.html#method.frames). Specifically: * `Backtrace::short_frames_strict`: reproduces the current behaviour of std where it only uses the two delimiter frames * `Backtrace::short_frames`: as above,...

tbc I'm happy to implement this if it will be accepted. until then i'm just going to implement the same logic in the above libraries to fix the ecosystem

> Also the libstd api allows you to choose if anything should be filtered or not. Also I couldn't find any such API in std::backtrace? Are you just referring to...

I've created the backtrace-ext crate with a [short_frames_strict function](https://docs.rs/backtrace-ext/latest/backtrace_ext/fn.short_frames_strict.html) as described above. miette now uses it.

@gabrielesvelto was there a tool/process you followed for this or did you like, literally clone their repo and copy the files over