Rustc --explain E0282; error: could not compile `time` (lib)

noblman · August 17, 2024, 8:02pm

I recently started getting errors when building my system. There are a number of packages that no longer build. I have had to remove them from my configuration in order to get my system to build.

They all give the same error message:

For more information about this error, try `rustc --explain E0282`.
error: could not compile `time` (lib) due to 1 previous error

The packages that won’t build are:

kakoune-lsp
ctpv
easyeffects
uair

Is this a problem with an upstream rust library that I just need to wait to be fixed? Is there anything I can do in the mean time? When this type of thing happens, can I roll back to a previous version of an package to see if it will build?

rnhmjoj · August 17, 2024, 8:09pm

github.com/NixOS/nixpkgs

Rust 1.80.0 breaks some packages

opened 09:32AM - 07 Aug 24 UTC

alyssais

6.topic: rust 5. scope: tracking

Dear maintainers, Rust 1.80.0 contains a couple of changes that break some pa…ckages: [an unfixable build regression](https://github.com/rust-lang/rust/issues/127343), and a warning for unrecognized cfg values that some packages treat as an error. Most commonly, the required fix is just to update the "time" crate. I've opened PRs to fix as many regressions as I can, but I can't do all of them. 1.80.0 is currently in staging-next, so will probably be in Nixpkgs master in the next 1-2 weeks. It wasn't really feasible to hold back, because packages tend to start requiring new Rust versions very soon after release, and it also didn't make a lot of sense to keep 1.79.0 as well, because many of the affected packages haven't been touched in a year or more, so there'd be no assurance we'd be able to remove it any time soon. So, some effort will be required from you to keep your package building with 1.80.0. Usually, the process will be like this: - Figure out what's broken. Usually, but not always, this is that the "time" crate needs to be updated. - Get it fixed upstream, if it isn't already. - Ask upstream to release a new version, if they haven't already. - Update the package in Nixpkgs. As a last resort, we can patch if we need to, but especially for packages that include a Cargo.lock in Nixpkgs, this is a pain. I'll post the affected packages in comments, because GitHub limits how many mentions an issue body can contain. Sorry for the inconvenience. I've lost a lot of the last week to coordinating the update, collecting broken packages, etc., but hopefully by spreading out the work from here it won't take too much of anybody else's time.

futile · August 17, 2024, 8:09pm

The error is because the rust compiler made a small breaking change, which causes old versions of time to no longer compile. See, e.g., here: `time` crate compilation error - #2 by DatoClement - help - The Rust Programming Language Forum

The fix is to update dependencies/to a newer version for those affected packages (or to compile them with an older rustc version, but well, not the ideal solution).

waffle8946 · August 18, 2024, 11:59am

Also for easyeffects, this was due to a dep (deepfilternet) which was fixed in deepfilternet: fix compilation with Rust 1.80 by Mrmaxmeier · Pull Request #334838 · NixOS/nixpkgs · GitHub.

So yeah for a lot of these, the answer is to just wait a couple days until it lands in nixos-unstable.