add basic "install from lock file" operation (#3340)

This PR principally adds a routine for converting a `Lock` to a
`Resolution`, where a `Resolution` is a map of package names pinned to
a specific version.

I'm not sure that a `Resolution` is ultimately what we want here (we
might need more stuff), but this was the quickest route I could find to
plug a `Lock` into our existing `uv pip install` infrastructure.

This commit also does a little refactoring of the `Lock` types. The
main thing is to permit extra state on some of the types (like a
`by_id` map on `Lock` for quick lookups of distributions) that aren't
included in the serialization format of a `Lock`. We achieve this
by defining separate `Wire` types that are automatically converted
to-and-from via `serde`.

Note that like with the lock file format types themselves, we leave a
few `todo!()` expressions around. The main idea is to get something
minimally working without spending too much effort here. (A fair bit
of refactoring will be required to generate a lock file, and it's
not clear how much this code will wind up needing to change anyway.)
In particular, we only handle the case of installing wheels from a
registry.

A demonstration of the full flow:

```
$ requirements.in
anyio
$ cargo run -p uv -- pip compile -p3.10 requirements.in --unstable-uv-lock-file
$ uv venv
$ cargo run -p uv -- pip install --unstable-uv-lock-file anyio -r requirements.in
Installed 5 packages in 7ms
 + anyio==4.3.0
 + exceptiongroup==1.2.1
 + idna==3.7
 + sniffio==1.3.1
 + typing-extensions==4.11.0
```

In order to install from a lock file, we start from the root and do a
breadth first traversal over its dependencies. We aren't yet filtering
on marker expressions (since they aren't in the lock file yet), but we
should be able to add that in the future. In so doing, the traversal
should select only the subset of distributions relevant for the current
platform.

crates/uv-resolver/src/lock.rs

@@ -1,27 +1,133 @@
 // Temporarily allowed because this module is still in a state of flux
 // as we build out universal locking.
-#![allow(dead_code, unreachable_code)]
+#![allow(dead_code, unreachable_code, unused_variables)]
 
+use std::collections::VecDeque;
+
+use distribution_filename::WheelFilename;
 use distribution_types::{
-    BuiltDist, DirectUrlBuiltDist, DirectUrlSourceDist, Dist, DistributionMetadata, GitSourceDist,
+    BuiltDist, DirectUrlBuiltDist, DirectUrlSourceDist, Dist, DistributionMetadata, FileLocation,
-    IndexUrl, Name, PathBuiltDist, PathSourceDist, RegistryBuiltDist, RegistrySourceDist,
+    GitSourceDist, IndexUrl, Name, PathBuiltDist, PathSourceDist, RegistryBuiltDist,
-    ResolvedDist, ToUrlError, VersionOrUrl,
+    RegistrySourceDist, Resolution, ResolvedDist, ToUrlError, VersionOrUrl,
 };
 use pep440_rs::Version;
+use pep508_rs::{MarkerEnvironment, VerbatimUrl};
+use platform_tags::{TagCompatibility, TagPriority, Tags};
 use pypi_types::HashDigest;
+use rustc_hash::FxHashMap;
 use url::Url;
+use uv_normalize::PackageName;
 
 #[derive(Clone, Debug)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "serde", serde(into = "LockWire", try_from = "LockWire"))]
 pub struct Lock {
+    version: u32,
+    distributions: Vec<Distribution>,
+    /// A map from distribution ID to index in `distributions`.
+    ///
+    /// This can be used to quickly lookup the full distribution for any ID
+    /// in this lock. For example, the dependencies for each distribution are
+    /// listed as distributions IDs. This map can be used to find the full
+    /// distribution for each such dependency.
+    ///
+    /// It is guaranteed that every distribution in this lock has an entry in
+    /// this map, and that every dependency for every distribution has an ID
+    /// that exists in this map. That is, there are no dependencies that don't
+    /// have a corresponding locked distribution entry in the same lock file.
+    by_id: FxHashMap<DistributionId, usize>,
+}
+
+impl Lock {
+    pub(crate) fn new(distributions: Vec<Distribution>) -> Result<Lock, LockError> {
+        let wire = LockWire {
+            version: 1,
+            distributions,
+        };
+        Lock::try_from(wire)
+    }
+
+    pub fn to_resolution(
+        &self,
+        marker_env: &MarkerEnvironment,
+        tags: &Tags,
+        root_name: &PackageName,
+    ) -> Resolution {
+        let root = self
+            .find_by_name(root_name)
+            // TODO: In the future, we should derive the root distribution
+            // from the pyproject.toml, but I don't think the infrastructure
+            // for that is in place yet. For now, we ask the caller to specify
+            // the root package name explicitly, and we assume here that it is
+            // correct.
+            .expect("found too many distributions matching root")
+            .expect("could not find root");
+        let mut queue: VecDeque<&Distribution> = VecDeque::new();
+        queue.push_back(root);
+
+        let mut map = FxHashMap::default();
+        while let Some(dist) = queue.pop_front() {
+            for dep in &dist.dependencies {
+                let dep_dist = self.find_by_id(&dep.id);
+                queue.push_back(dep_dist);
+            }
+            let name = PackageName::new(dist.id.name.to_string()).unwrap();
+            let resolved_dist = ResolvedDist::Installable(dist.to_dist(marker_env, tags));
+            map.insert(name, resolved_dist);
+        }
+        Resolution::new(map)
+    }
+
+    /// Returns the distribution with the given name. If there are multiple
+    /// matching distributions, then an error is returned. If there are no
+    /// matching distributions, then `Ok(None)` is returned.
+    fn find_by_name(&self, name: &PackageName) -> Result<Option<&Distribution>, String> {
+        let mut found_dist = None;
+        for dist in &self.distributions {
+            if &dist.id.name == name {
+                if found_dist.is_some() {
+                    return Err(format!("found multiple distributions matching `{name}`"));
+                }
+                found_dist = Some(dist);
+            }
+        }
+        Ok(found_dist)
+    }
+
+    fn find_by_id(&self, id: &DistributionId) -> &Distribution {
+        let index = *self.by_id.get(id).expect("locked distribution for ID");
+        let dist = self
+            .distributions
+            .get(index)
+            .expect("valid index for distribution");
+        dist
+    }
+}
+
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+struct LockWire {
     version: u32,
     #[cfg_attr(feature = "serde", serde(rename = "distribution"))]
     distributions: Vec<Distribution>,
 }
 
-impl Lock {
+impl From<Lock> for LockWire {
-    pub(crate) fn new(mut distributions: Vec<Distribution>) -> Result<Lock, LockError> {
+    fn from(lock: Lock) -> LockWire {
-        for dist in &mut distributions {
+        LockWire {
+            version: lock.version,
+            distributions: lock.distributions,
+        }
+    }
+}
+
+impl TryFrom<LockWire> for Lock {
+    type Error = LockError;
+
+    fn try_from(mut wire: LockWire) -> Result<Lock, LockError> {
+        // Put all dependencies for each distribution in a canonical order and
+        // check for duplicates.
+        for dist in &mut wire.distributions {
             dist.dependencies.sort();
             for windows in dist.dependencies.windows(2) {
                 let (dep1, dep2) = (&windows[0], &windows[1]);
@@ -33,16 +139,34 @@ impl Lock {
                 }
             }
         }
-        distributions.sort_by(|dist1, dist2| dist1.id.cmp(&dist2.id));
+        wire.distributions
-        for window in distributions.windows(2) {
+            .sort_by(|dist1, dist2| dist1.id.cmp(&dist2.id));
-            let (dist1, dist2) = (&window[0], &window[1]);
+
-            if dist1.id == dist2.id {
+        // Check for duplicate distribution IDs and also build up the map for
-                return Err(LockError::duplicate_distribution(dist1.id.clone()));
+        // distributions keyed by their ID.
+        let mut by_id = FxHashMap::default();
+        for (i, dist) in wire.distributions.iter().enumerate() {
+            if by_id.insert(dist.id.clone(), i).is_some() {
+                return Err(LockError::duplicate_distribution(dist.id.clone()));
+            }
+        }
+        // Check that every dependency has an entry in `by_id`. If any don't,
+        // it implies we somehow have a dependency with no corresponding locked
+        // distribution.
+        for dist in &wire.distributions {
+            for dep in &dist.dependencies {
+                if !by_id.contains_key(&dep.id) {
+                    return Err(LockError::unrecognized_dependency(
+                        dist.id.clone(),
+                        dep.id.clone(),
+                    ));
+                }
             }
         }
         Ok(Lock {
-            version: 1,
+            version: wire.version,
-            distributions,
+            distributions: wire.distributions,
+            by_id,
         })
     }
 }
@@ -52,14 +176,19 @@ impl Lock {
 pub(crate) struct Distribution {
     #[cfg_attr(feature = "serde", serde(flatten))]
     pub(crate) id: DistributionId,
+    #[cfg_attr(feature = "serde", serde(default))]
     pub(crate) marker: Option<String>,
+    #[cfg_attr(feature = "serde", serde(default))]
     pub(crate) sourcedist: Option<SourceDist>,
     #[cfg_attr(
         feature = "serde",
-        serde(rename = "wheel", skip_serializing_if = "Vec::is_empty")
+        serde(default, rename = "wheel", skip_serializing_if = "Vec::is_empty")
     )]
     pub(crate) wheels: Vec<Wheel>,
-    #[cfg_attr(feature = "serde", serde(skip_serializing_if = "Vec::is_empty"))]
+    #[cfg_attr(
+        feature = "serde",
+        serde(default, skip_serializing_if = "Vec::is_empty")
+    )]
     pub(crate) dependencies: Vec<Dependency>,
 }
 
@@ -90,19 +219,73 @@ impl Distribution {
         self.dependencies
             .push(Dependency::from_resolved_dist(resolved_dist));
     }
+
+    fn to_dist(&self, _marker_env: &MarkerEnvironment, tags: &Tags) -> Dist {
+        if let Some(wheel) = self.find_best_wheel(tags) {
+            return match self.id.source.kind {
+                SourceKind::Registry => {
+                    let filename: WheelFilename = wheel.filename.clone();
+                    let file = Box::new(distribution_types::File {
+                        dist_info_metadata: false,
+                        filename: filename.to_string(),
+                        hashes: vec![],
+                        requires_python: None,
+                        size: None,
+                        upload_time_utc_ms: None,
+                        url: FileLocation::AbsoluteUrl(wheel.url.to_string()),
+                        yanked: None,
+                    });
+                    let index = IndexUrl::Pypi(VerbatimUrl::from_url(self.id.source.url.clone()));
+                    let reg_dist = RegistryBuiltDist {
+                        filename,
+                        file,
+                        index,
+                    };
+                    let built_dist = BuiltDist::Registry(reg_dist);
+                    Dist::Built(built_dist)
+                }
+                // TODO: Handle other kinds of sources.
+                _ => todo!(),
+            };
+        }
+        // TODO: Handle source dists.
+
+        // TODO: Convert this to a deserialization error.
+        panic!("invalid lock distribution")
     }
 
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+    fn find_best_wheel(&self, tags: &Tags) -> Option<&Wheel> {
+        let mut best: Option<(TagPriority, &Wheel)> = None;
+        for wheel in &self.wheels {
+            let TagCompatibility::Compatible(priority) = wheel.filename.compatibility(tags) else {
+                continue;
+            };
+            match best {
+                None => {
+                    best = Some((priority, wheel));
+                }
+                Some((best_priority, _)) => {
+                    if priority > best_priority {
+                        best = Some((priority, wheel));
+                    }
+                }
+            }
+        }
+        best.map(|(_, wheel)| wheel)
+    }
+}
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub(crate) struct DistributionId {
-    pub(crate) name: String,
+    pub(crate) name: PackageName,
     pub(crate) version: Version,
     pub(crate) source: Source,
 }
 
 impl DistributionId {
     fn from_resolved_dist(resolved_dist: &ResolvedDist) -> DistributionId {
-        let name = resolved_dist.name().to_string();
+        let name = resolved_dist.name().clone();
         let version = match resolved_dist.version_or_url() {
             VersionOrUrl::Version(v) => v.clone(),
             // TODO: We need a way to thread the version number for these
@@ -125,7 +308,7 @@ impl std::fmt::Display for DistributionId {
     }
 }
 
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub(crate) struct Source {
     kind: SourceKind,
     url: Url,
@@ -298,7 +481,7 @@ impl<'de> serde::Deserialize<'de> for Source {
 /// variants should be added without changing the relative ordering of other
 /// variants. Otherwise, this could cause the lock file to have a different
 /// canonical ordering of distributions.
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 #[cfg_attr(feature = "serde", serde(rename_all = "kebab-case"))]
 pub(crate) enum SourceKind {
@@ -323,7 +506,7 @@ impl SourceKind {
 /// variants should be added without changing the relative ordering of other
 /// variants. Otherwise, this could cause the lock file to have a different
 /// canonical ordering of distributions.
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub(crate) struct GitSource {
     precise: Option<String>,
@@ -353,7 +536,7 @@ impl GitSource {
     }
 }
 
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 enum GitSourceKind {
     Tag(String),
@@ -451,6 +634,7 @@ impl SourceDist {
 /// Inspired by: <https://discuss.python.org/t/lock-files-again-but-this-time-w-sdists/46593>
 #[derive(Clone, Debug)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "serde", serde(into = "WheelWire", try_from = "WheelWire"))]
 pub(crate) struct Wheel {
     /// A URL or file path (via `file://`) where the wheel that was locked
     /// against was found. The location does not need to exist in the future,
@@ -459,13 +643,13 @@ pub(crate) struct Wheel {
     url: Url,
     /// A hash of the source distribution.
     hash: Hash,
-    // THOUGHT: Would it be better to include a more structured representation
+    /// The filename of the wheel.
-    // of the wheel's filename in the lock file itself? e.g., All of the wheel
+    ///
-    // tags. This would avoid needing to parse the wheel tags out of the URL,
+    /// This isn't part of the wire format since it's redundant with the
-    // which is a potentially fallible operation. But, I think it is nice to
+    /// URL. But we do use it for various things, and thus compute it at
-    // have just the URL which is more succinct and doesn't result in encoding
+    /// deserialization time. Not being able to extract a wheel filename from a
-    // the same information twice. Probably the best thing to do here is to add
+    /// wheel URL is thus a deserialization error.
-    // the wheel tags fields here, but don't serialize them.
+    filename: WheelFilename,
 }
 
 impl Wheel {
@@ -496,13 +680,18 @@ impl Wheel {
     fn from_registry_dist(reg_dist: &RegistryBuiltDist) -> Result<Wheel, LockError> {
         // FIXME: Is it guaranteed that there is at least one hash?
         // If not, we probably need to make this fallible.
+        let filename = reg_dist.filename.clone();
         let url = reg_dist
             .file
             .url
             .to_url()
             .map_err(LockError::invalid_file_url)?;
         let hash = Hash::from(reg_dist.file.hashes[0].clone());
-        Ok(Wheel { url, hash })
+        Ok(Wheel {
+            url,
+            hash,
+            filename,
+        })
     }
 
     fn from_direct_dist(direct_dist: &DirectUrlBuiltDist) -> Wheel {
@@ -510,6 +699,7 @@ impl Wheel {
             url: direct_dist.url.to_url(),
             // TODO: We want a hash for the artifact at the URL.
             hash: todo!(),
+            filename: direct_dist.filename.clone(),
         }
     }
 
@@ -518,10 +708,53 @@ impl Wheel {
             url: path_dist.url.to_url(),
             // TODO: We want a hash for the artifact at the URL.
             hash: todo!(),
+            filename: path_dist.filename.clone(),
         }
     }
 }
 
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+struct WheelWire {
+    /// A URL or file path (via `file://`) where the wheel that was locked
+    /// against was found. The location does not need to exist in the future,
+    /// so this should be treated as only a hint to where to look and/or
+    /// recording where the wheel file originally came from.
+    url: Url,
+    /// A hash of the source distribution.
+    hash: Hash,
+}
+
+impl From<Wheel> for WheelWire {
+    fn from(wheel: Wheel) -> WheelWire {
+        WheelWire {
+            url: wheel.url,
+            hash: wheel.hash,
+        }
+    }
+}
+
+impl TryFrom<WheelWire> for Wheel {
+    type Error = String;
+
+    fn try_from(wire: WheelWire) -> Result<Wheel, String> {
+        let path_segments = wire
+            .url
+            .path_segments()
+            .ok_or_else(|| format!("could not extract path from URL `{}`", wire.url))?;
+        // This is guaranteed by the contract of Url::path_segments.
+        let last = path_segments.last().expect("path segments is non-empty");
+        let filename = last
+            .parse::<WheelFilename>()
+            .map_err(|err| format!("failed to parse `{last}` as wheel filename: {err}"))?;
+        Ok(Wheel {
+            url: wire.url,
+            hash: wire.hash,
+            filename,
+        })
+    }
+}
+
 /// A single dependency of a distribution in a lock file.
 #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
@@ -626,6 +859,14 @@ impl LockError {
             kind: Box::new(kind),
         }
     }
+
+    fn unrecognized_dependency(id: DistributionId, dependency_id: DistributionId) -> LockError {
+        let err = UnrecognizedDependencyError { id, dependency_id };
+        let kind = LockErrorKind::UnrecognizedDependency { err };
+        LockError {
+            kind: Box::new(kind),
+        }
+    }
 }
 
 impl std::error::Error for LockError {
@@ -634,6 +875,7 @@ impl std::error::Error for LockError {
             LockErrorKind::DuplicateDistribution { .. } => None,
             LockErrorKind::DuplicateDependency { .. } => None,
             LockErrorKind::InvalidFileUrl { ref err } => Some(err),
+            LockErrorKind::UnrecognizedDependency { ref err } => Some(err),
         }
     }
 }
@@ -656,6 +898,9 @@ impl std::fmt::Display for LockError {
             LockErrorKind::InvalidFileUrl { .. } => {
                 write!(f, "failed to parse wheel or source dist URL")
             }
+            LockErrorKind::UnrecognizedDependency { .. } => {
+                write!(f, "found unrecognized dependency")
+            }
         }
     }
 }
@@ -684,6 +929,40 @@ enum LockErrorKind {
         /// errant URL in its error message.
         err: ToUrlError,
     },
+    /// An error that occurs when the caller provides a distribution with a
+    /// dependency that doesn't correspond to any other distribution in the
+    /// lock file.
+    UnrecognizedDependency {
+        /// The actual error.
+        err: UnrecognizedDependencyError,
+    },
+}
+
+/// An error that occurs when there's an unrecognized dependency.
+///
+/// That is, a dependency for a distribution that isn't in the lock file.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub(crate) struct UnrecognizedDependencyError {
+    /// The ID of the distribution that has an unrecognized dependency.
+    id: DistributionId,
+    /// The ID of the dependency that doesn't have a corresponding distribution
+    /// entry.
+    dependency_id: DistributionId,
+}
+
+impl std::error::Error for UnrecognizedDependencyError {}
+
+impl std::fmt::Display for UnrecognizedDependencyError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        let UnrecognizedDependencyError {
+            ref id,
+            ref dependency_id,
+        } = *self;
+        write!(
+            f,
+            "found dependency `{dependency_id}` for `{id}` with no locked distribution"
+        )
+    }
 }
 
 /// An error that occurs when a source string could not be parsed.

crates/uv/src/cli.rs

@@ -1329,6 +1329,9 @@ pub(crate) struct PipInstallArgs {
     /// print the resulting plan.
     #[arg(long)]
     pub(crate) dry_run: bool,
+
+    #[arg(long, hide = true)]
+    pub(crate) unstable_uv_lock_file: Option<String>,
 }
 
 #[derive(Args)]

crates/uv/src/commands/pip_install.rs

@@ -4,6 +4,7 @@ use std::path::Path;
 
 use anstream::eprint;
 use anyhow::{anyhow, Context, Result};
+use fs_err as fs;
 use itertools::Itertools;
 use owo_colors::OwoColorize;
 use tempfile::tempdir_in;
@@ -40,7 +41,7 @@ use uv_requirements::{
     RequirementsSpecification, SourceTreeResolver,
 };
 use uv_resolver::{
-    DependencyMode, ExcludeNewer, Exclusions, FlatIndex, InMemoryIndex, Manifest, Options,
+    DependencyMode, ExcludeNewer, Exclusions, FlatIndex, InMemoryIndex, Lock, Manifest, Options,
     OptionsBuilder, PreReleaseMode, Preference, ResolutionGraph, ResolutionMode, Resolver,
 };
 use uv_types::{BuildIsolation, HashStrategy, InFlight};
@@ -84,6 +85,7 @@ pub(crate) async fn pip_install(
     system: bool,
     break_system_packages: bool,
     target: Option<Target>,
+    uv_lock: Option<String>,
     native_tls: bool,
     cache: Cache,
     dry_run: bool,
@@ -329,6 +331,35 @@ pub(crate) async fn pip_install(
     )
     .with_options(OptionsBuilder::new().exclude_newer(exclude_newer).build());
 
+    // Build all editable distributions. The editables are shared between resolution and
+    // installation, and should live for the duration of the command. If an editable is already
+    // installed in the environment, we'll still re-build it here.
+    let editable_wheel_dir;
+    let editables = if editables.is_empty() {
+        vec![]
+    } else {
+        editable_wheel_dir = tempdir_in(cache.root())?;
+        build_editables(
+            &editables,
+            editable_wheel_dir.path(),
+            &hasher,
+            &cache,
+            &interpreter,
+            &tags,
+            &client,
+            &resolve_dispatch,
+            printer,
+        )
+        .await?
+    };
+
+    // Resolve the requirements.
+    let resolution = if let Some(ref root) = uv_lock {
+        let root = PackageName::new(root.to_string())?;
+        let encoded = fs::tokio::read_to_string("uv.lock").await?;
+        let lock: Lock = toml::from_str(&encoded)?;
+        lock.to_resolution(&markers, &tags, &root)
+    } else {
         // Resolve the requirements from the provided sources.
         let requirements = {
             // Convert from unnamed to named requirements.
@@ -370,28 +401,6 @@ pub(crate) async fn pip_install(
                 .resolve()
                 .await?;
 
-    // Build all editable distributions. The editables are shared between resolution and
-    // installation, and should live for the duration of the command. If an editable is already
-    // installed in the environment, we'll still re-build it here.
-    let editable_wheel_dir;
-    let editables = if editables.is_empty() {
-        vec![]
-    } else {
-        editable_wheel_dir = tempdir_in(cache.root())?;
-        build_editables(
-            &editables,
-            editable_wheel_dir.path(),
-            &hasher,
-            &cache,
-            &interpreter,
-            &tags,
-            &client,
-            &resolve_dispatch,
-            printer,
-        )
-        .await?
-    };
-
         let options = OptionsBuilder::new()
             .resolution_mode(resolution_mode)
             .prerelease_mode(prerelease_mode)
@@ -400,8 +409,7 @@ pub(crate) async fn pip_install(
             .index_strategy(index_strategy)
             .build();
 
-    // Resolve the requirements.
+        match resolve(
-    let resolution = match resolve(
             requirements,
             constraints,
             overrides,
@@ -431,6 +439,7 @@ pub(crate) async fn pip_install(
                 return Ok(ExitStatus::Failure);
             }
             Err(err) => return Err(err.into()),
+        }
     };
 
     // Re-initialize the in-flight map.

crates/uv/src/main.rs

@@ -339,6 +339,7 @@ async fn run() -> Result<ExitStatus> {
                 args.shared.system,
                 args.shared.break_system_packages,
                 args.shared.target,
+                args.uv_lock,
                 globals.native_tls,
                 cache,
                 args.dry_run,

crates/uv/src/settings.rs

@@ -390,6 +390,7 @@ pub(crate) struct PipInstallSettings {
     pub(crate) reinstall: Reinstall,
     pub(crate) refresh: Refresh,
     pub(crate) dry_run: bool,
+    pub(crate) uv_lock: Option<String>,
     // Shared settings.
     pub(crate) shared: PipSharedSettings,
 }
@@ -454,6 +455,7 @@ impl PipInstallSettings {
             no_strict,
             exclude_newer,
             dry_run,
+            unstable_uv_lock_file,
         } = args;
 
         Self {
@@ -470,6 +472,7 @@ impl PipInstallSettings {
             reinstall: Reinstall::from_args(flag(reinstall, no_reinstall), reinstall_package),
             refresh: Refresh::from_args(flag(refresh, no_refresh), refresh_package),
             dry_run,
+            uv_lock: unstable_uv_lock_file,
 
             // Shared settings.
             shared: PipSharedSettings::combine(