## Summary
This PR declares and documents all environment variables that are used
in one way or another in `uv`, either internally, or externally, or
transitively under a common struct.
I think over time as uv has grown there's been many environment
variables introduced. Its harder to know which ones exists, which ones
are missing, what they're used for, or where are they used across the
code. The docs only documents a handful of them, for others you'd have
to dive into the code and inspect across crates to know which crates
they're used on or where they're relevant.
This PR is a starting attempt to unify them, make it easier to discover
which ones we have, and maybe unlock future posibilities in automating
generating documentation for them.
I think we can split out into multiple structs later to better organize,
but given the high influx of PR's and possibly new environment variables
introduced/re-used, it would be hard to try to organize them all now
into their proper namespaced struct while this is all happening given
merge conflicts and/or keeping up to date.
I don't think this has any impact on performance as they all should
still be inlined, although it may affect local build times on changes to
the environment vars as more crates would likely need a rebuild. Lastly,
some of them are declared but not used in the code, for example those in
`build.rs`. I left them declared because I still think it's useful to at
least have a reference.
Did I miss any? Are their initial docs cohesive?
Note, `uv-static` is a terrible name for a new crate, thoughts? Others
considered `uv-vars`, `uv-consts`.
## Test Plan
Existing tests
As per
https://matklad.github.io/2021/02/27/delete-cargo-integration-tests.html
Before that, there were 91 separate integration tests binary.
(As discussed on Discord — I've done the `uv` crate, there's still a few
more commits coming before this is mergeable, and I want to see how it
performs in CI and locally).
## Summary
This PR changes the definition of `--locked` from:
> Produces the same `Lock`
To:
> Passes `Lock::satisfies`
This is a subtle but important difference. Previous, if
`Lock::satisfies` failed, we would run a resolution, then do
`existing_lock == lock`. If the two weren't equal, and `--locked` was
specified, we'd throw an error.
The equality check is hard to get right. For example, it means that we
can't ship #6076 without changing our marker representation, since the
deserialized lockfile "loses" some of the internal marker state that
gets accumulated during resolution.
The downside of this change is that there could be scenarios in which
`uv lock --locked` fails even though the lockfile would actually work
and the exact TOML would be unchanged. But... I think it's ok if
`--locked` fails after the user modifies something?
## Summary
Historically, in order to "resolve from a lockfile", we've taken the
lockfile, used it to pre-populate the in-memory metadata index, then run
a resolution. If the resolution didn't match our existing resolution, we
re-resolved from scratch.
This was an appealing approach because (in theory) it didn't require any
dedicated logic beyond pre-populating the index. However, it's proven to
be _really_ hard to get right, because it's a stricter requirement than
we need. We just need the current lockfile to _satisfy_ the requirements
provided by the user. We don't actually need a second resolution to
produce the exact same result. And it's not uncommon that this second
resolution differs, because we seed it with preferences, which
fundamentally changes its course. We've worked hard to minimize those
"instabilities", but they're still present.
The approach here is intended to be much simpler. Instead of resolving
from the lockfile, we just check if the current resolution satisfies the
state of the workspace. Specifically, we check if the lockfile (1)
contains all the relevant members, and (2) matches the metadata for all
dependencies, recursively. (We skip registry dependencies, assuming that
they're immutable.)
This may actually be too conservative, since we can have resolutions
that satisfy the requirements, even if the requirements have changed
slightly. But we want to bias towards correctness for now.
My hope is that this scheme will be more performant, simpler, and more
robust.
Closes https://github.com/astral-sh/uv/issues/6063.
## Summary
Now, if you resolve against a registry, then swap it out for another, we
won't reuse the lockfile. (If you don't provide any registry
configuration, then we won't enforce this, so that `uv lock --index-url
foo` and `uv lock` is stable.)
Closes https://github.com/astral-sh/uv/issues/5920.
Every packse version update is currently causing a huge diff (the size
of the `lock_scenarios.rs` diff in this PR). By redacting the version
from the snapshots, we will only have the actual change in the diff and
not the redundant version change noise.
The second commit moves all remaining packse url arg values to
`common/mod.rs`, which acts as a single source of truth for the packse
version.
packse has the ability to specify a project wide Requires-Python
constraint, but our lock template wasn't forwarding this to the
corresponding pyproject.toml. This update makes that happen.
This commit adds a template and does some light surgery on `generate.py`
to make use of that template. In particular, the universal tests require
using the "workspace"-aware version of `uv`, so we can't use the
existing `uv pip {compile,install}` tests.
konsti