This asymmetry is well understood by marketing and PR professionals, and actively exploited.
It is. We’re what, a week into this exercise? Absolutely everyone criticizing it, with no exceptions, is behaving like a micromanaging middle manager who couldn’t even dream of doing the work themselves.
I half want to start a list of “people to ignore”, but such people tend to expose themselves in every other comment anyway.
And realistically, essentially 100% of the people criticizing this don't have the the credentials to do so meaningfully.
Did they even claim it was "memory-safe"? Every discussion of this topic has had dozens of comments noting that their vibed codebase is bursting at the seams with unaudited unsafe blocks, lightly reviewed by people who seem to not only seem to not understand Rust, but who seem incensed at the idea of needing to understand any programming language in the first place.
The "1:1" assumption is a massive unjustified assumption. Rust and Zig have different memory models, so it's possible to do a "1:1" translation of Zig code to Rust and end up with undefined behavior in Rust.
For example, Zig code might make assumptions about lifetimes based on implicit knowledge of which allocator was used for some memory. That could cause problems in Rust if you erase the lifetime https://github.com/oven-sh/bun/blob/main/src/bun_core/string...
It's not, that's clear from this kind of bug popping up. Functionally this bug exists because `PathString` was converted into a "safe" Rust API but still works the same internally as the original Zig code did (via using `unsafe`), that introduces UB that wasn't there in the Zig code.
If it was attempting to be a 1:1 with no behavior changes (like c2Rust attempts to do) then this would not have been turned into a "safe" Rust API like this.
They did cite Rust's safety as a motivating factor for the port. That doesn't imply trying to achieve that simultaneously with the language change — which is good, because that would be insane. (Or, if you prefer, even more insane.)
You cannot faithfully port a codebase to a new language while also radically re-architecting it. You have to choose.
They want the safety benefits of Rust going forward; i.e., after it's finished, when they then write new code in Rust.
The newer posts go into detail about the rearchitecting that follows.
It's simply not possible to include all the nuance of safety of a language and all software written in it a single word. This leads to all kinds of miscommunication and strawmanning.
Rust's official line is specific memory safety guarantees, with caveats that it must not be broken by unsafe code, the OS, compiler bugs may happen, etc. Rust also has a bunch of best-effort features that steer users towards more robust code, but can't guarantee it.
This gets twisted in both directions:
- people ignore the caveats and limitations, pretending that Rust promised zero bugs ever, and use any bug in any Rust program as a proof by contradiction that Rust's claims are false.
- or focus solely on the caveats, ignoring all the advancements and incremental improvements, and take a "then why even bother?" There are classes of bugs Rust can't stop. Nothing is foolproof for a sufficiently advanced fool, and an infallible programmer could write bug-free code in any language, which creates a false equivalence between languages.
they didn't,
actually the port is trying to be mostly 1:1 and in turn is mostly unsafe rust, which means no benefits initially
but also doing the 1:1 port to mostly unsafe rust is also only the first step of a full port, you then incrementally go through it fixing issues and remove "unsafe" usage. (And long term likely also doing some refactoring to using more idiomatic rust, but that has less priority).
The problem is there was no blog port describing the whole thing to someone without contextual knowledge. Instead just linked PRs which is in this case somewhat close to a "as if nearly all people only read the HN headline" case :/
Like a more context giving version of the first HN post would have something on the line of `Show HN: Bun is porting to safe rust (PR link), starting with an AI based automatized port to mostly unsafe rust which once it behaves mostly the same as Bun in the test suite will likely be merged. But must be followed up with incremental PRs to remove unsafeness, and likely also a lot of unsoundness related to the way it's ported (some explanation about why this port will have unsoundness).`
In your quote, there is no time-dependency between the lie and the truth. Whereas here, it's an attractive lie (easily parsed, great narrative), followed up by truths (that need more than surface-level analysis).
The rewrite was a code translation meant to be a starting point.
> a big, flashy announcement (here: bun was re-written in memory-safe rust in a couple weeks), and the relatively small reach of a correction (often just a footnote on an old article, here a GH issue).
The Bun team never made a big announcement that the code is now memory safe. They've been clear that this is the starting point.
Anyone expecting it to be perfect immediately and to have solved all of the memory problems in the original Zig code is arguing with an announcement they imagined, not what the Bun team has said.
Did anyone try to map this code back to the original codebase to see if this memory problem exists in the original codebase?
FWIW what is being discussed is not memory problems, it's breaking rust invariants (the unsafe code has to follow specific rules, e.g. annotate lifetimes properly).
c’mon.