The popular Rust tool "ripgrep" uses a lock file for development (you can see it in the GitHub repo), and yet is in the official repositories for homebrew, various Windows package managers, Arch, Gentoo, Fedora, some versions of openSUSE, Guix, recent versions of Debian (and therefore Ubuntu), FreeBSD, OpenBSD, NetBSD, and Haiku.
With all due respect, I don't think you're correct.
And how much rust software is packaged in distributions? Almost none. They haven't figured out the procedures, because distributions really really don't want pinned stuff around.
Homebrew, windows, arch all have very very relaxed processes to enter. There is no QA, you can just do whatever you want. I mean more like Fedora and Debian.
Bottom line is that the lock file in ripgrep's repo hasn't prevented it from being packaged. And I haven't heard of any distro maintainer complain about any lock file in any Rust program ever. So you're just plain empirically wrong about lock files preventing Rust programs from being packaged.
You've now moved on to talking about something else, which is "how much Rust software is packaged." Well, apparently enough that Debian has Rust packaging policy[1]. I'll give you one guess at what isn't mentioned in that policy. Give up? Lock files!
How Linux package managers handle these newer languages with their own package managers (including rust) is an ongoing pain point. Here’s an article from 2017 about it, and I don’t know if things have improved:
The distros will eventually stop this dangerous practice of mixing and matching versions for all dependencies. It can only work for a small set of system components, which is what every other OS does.
Distros can keep their own lock file that is based on their own release branch's versions. If it doesn't build, the pkg maintainer will either file a bug report or make a patch, or neither.
But something building doesn't mean that it will work.
There can be changes that are different than function signature changes.
Where dependency pinning is the norm, there is a culture of breaking API compatibility. And you might not have a compiler error to inform you that the API has changed. Sometimes all you have is a commit message.
With all due respect, I don't think you're correct.