I maintain a ~250K LoC Zig compiler code base [0]. We've been through several breaking Zig releases (although the code base was much smaller for most of that time; Writergate is the main one we've had to deal with since the code base crossed the 100K LoC mark).

The language and stdlib changing hasn't been a major pain point in at least a year or two. There was some upgrade a couple of years ago that took us awhile to land (I think it might have been 0.12 -> 0.13 but I could be misremembering the exact version) but it's been smooth sailing for a long time now.

These days I'd put breaking releases in the "minor nuisance" category, and when people ask what I've liked and disliked about using Zig I rarely even remember to bring it up.

[0]: https://github.com/roc-lang/roc

Zig 0.15 is pretty stable. The biggest issue I face daily are silent compiler errors (SIGBUS) for trivial things, e.g. a typo in an import path. I've yet to find exactly why this [only sometimes] causes such a crash, but they're a real pain to figure out over a large changeset. `zig ast-check` sometimes catches the error, else Claude's pretty good at spotting where I accidentally re-used a variable name (again, 90% of the time I do that, it's an easy error, but the other 10%, I get a message-less compiler crash). It sounds like the changes in the OP might be specifically addressing these types of issues.

Also, my .zig-cache is currently at 173GB, which causes some issues on the small Linux ARM VPS I test with.

As for upgrades. I upgraded lightpanda to 0.14 then 0.15 and it was fine. I think for lightpanda, the 0.16 changes might not be too bad, with the only potential issue coming from our use of libcurl and our small websocket server (for CDP connections). Those layers are relatively isolated / abstracted, so I'm hopeful.

As a library developer, I've given up following / tracking 0.16. For one, the change don't resonate with me, and for another, it's changing far too fast. I don't think anyone expects 0.16 support in a library right now. I've gotten PRs for my "dev" branches from a few brave souls and everyone seems happy with that arrangement.

I stopped updating the compiler at 0.14 for three projects. Getting the correct toolchain is part of my (incremental) build process. I don't use any external Zig packages.

I think one of the more PITA changes necessary to get these projects to 0.15 is removing `usingnamespace`, which I've used to implement a kind of mixin. The projects are all a few thousand LOC and it shouldn't be that much trouble, but enough trouble that none of what I gain from upgrading currently justify doing it. I think that's fine.

For those like me who have never heard of this software: Bun, some sort of package management service for javascript. https://en.wikipedia.org/wiki/Bun_(software)

The language itself does not change much, but the std does. It depends on individuals, but some people rely less on the std, some copy the old code that they still need.

> Are there cases where packages you may use fall behind the language?

Using third party packages is quite problematic yes. I don't recommend using them too much personally, unless you want to make more work for yourself.

I recently tried to learn it and found it frustrating. A lot of docs are for 0.15 but the latest is (or was) 0.16 which changed a lot of std so none of the existing write ups were valid anymore. I plan to revisit once it gets more stable because I do like it when I get it to work.