This PR migrates uv's use of `chrono` to `jiff`.
I did most of this work a while back as one of my tests to ensure Jiff
could actually be used in a real world project. I decided to revive
this because I noticed that `reqwest-retry` dropped its Chrono
dependency,
which is I believe the only other thing requiring Chrono in uv.
(Although, we use a fork of `reqwest-middleware` at present, and that
hasn't been updated to latest upstream yet. I wasn't quite sure of the
process we have for that.)
In course of doing this, I actually made two changes to uv:
First is that the lock file now writes an RFC 3339 timestamp for
`exclude-newer`. Previously, we were using Chrono's `Display`
implementation for this which is a non-standard but "human readable"
format. I think the right thing to do here is an RFC 3339 timestamp.
Second is that, in addition to an RFC 3339 timestamp, `--exclude-newer`
used to accept a "UTC date." But this PR changes it to a "local date."
That is, a date in the user's system configured time zone. I think
this makes more sense than a UTC date, but one alternative is to drop
support for a date and just rely on an RFC 3339 timestamp. The main
motivation here is that automatically assuming UTC is often somewhat
confusing, since just writing an unqualified date like `2024-08-19` is
often assumed to be interpreted relative to the writer's "local" time.
## Summary
This PR modifies the lockfile to include the impactful resolution
settings, like the resolution and pre-release mode. If any of those
values change, we want to ignore the existing lockfile. Otherwise,
`--resolution lowest-direct` will typically have no effect, which is
really unintuitive.
Closes https://github.com/astral-sh/uv/issues/5226.
In *some* places in our crates, `serde` (and `rkyv`) are optional
dependencies. I believe this was done out of reasons of "good sense,"
that is, it follows a Rust ecosystem pattern where serde integration
tends to be an opt-in crate feature. (And similarly for `rkyv`.)
However, ultimately, `uv` itself requires `serde` and `rkyv` to
function. Since our crates are strictly internal, there are limited
consumers for our crates without `serde` (and `rkyv`) enabled. I think
one possibility is that optional `serde` (and `rkyv`) integration means
that someone can do this:
cargo test -p pep440_rs
And this will run tests _without_ `serde` or `rkyv` enabled. That in
turn could lead to faster iteration time by reducing compile times. But,
I'm not sure this is worth supporting. The iterative compilation times
of
individual crates are probably fast enough in debug mode, even with
`serde` and `rkyv` enabled. Namely, `serde` and `rkyv` themselves
shouldn't need to be re-compiled in most cases. On `main`:
```
from-scratch: `cargo test -p pep440_rs --lib` 0.685
incremental: `cargo test -p pep440_rs --lib` 0.278s
from-scratch: `cargo test -p pep440_rs --features serde,rkyv --lib` 3.948s
incremental: `cargo test -p pep440_rs --features serde,rkyv --lib` 0.321s
```
So while a from-scratch build does take significantly longer, an
incremental build is about the same.
The benefit of doing this change is two-fold:
1. It brings out crates into alignment with "reality." In particular,
some crates were _implicitly_ relying on `serde` being enabled
without explicitly declaring it. This technically means that our
`Cargo.toml`s were wrong in some cases, but it is hard to observe it
because of feature unification in a Cargo workspace.
2. We no longer need to deal with the cognitive burden of writing
`#[cfg_attr(feature = "serde", ...)]` everywhere.
## Summary
This PR adds basic struct definitions along with a "workspace" concept
for discovering settings. (The "workspace" terminology is used to match
Ruff; I did not invent it.)
A few notes:
- We discover any `pyproject.toml` or `uv.toml` file in any parent
directory of the current working directory. (We could adjust this to
look at the directories of the input files.)
- We don't actually do anything with the configuration yet; but those
PRs are large and I want this to be reviewed in isolation.
## Summary
This makes it easier to add (e.g.) JSON Schema derivations to the type.
If we have support for other dates in the future, we can generalize it
to a `UserDate` or similar.
