//! Given a set of requirements, find a set of compatible packages. use std::borrow::Cow; use std::cmp::Ordering; use std::collections::{BTreeMap, BTreeSet, VecDeque}; use std::fmt::{Display, Formatter, Write}; use std::ops::Bound; use std::sync::Arc; use std::time::Instant; use std::{iter, thread}; use dashmap::DashMap; use either::Either; use futures::{FutureExt, StreamExt}; use itertools::Itertools; use pubgrub::{Incompatibility, Range, State}; use rustc_hash::{FxHashMap, FxHashSet}; use tokio::sync::mpsc::{self, Receiver, Sender}; use tokio::sync::oneshot; use tokio_stream::wrappers::ReceiverStream; use tracing::{debug, info, instrument, trace, warn, Level}; use environment::ForkingPossibility; pub use environment::ResolverEnvironment; pub(crate) use fork_map::{ForkMap, ForkSet}; pub(crate) use urls::Urls; use uv_configuration::{Constraints, Overrides}; use uv_distribution::{ArchiveMetadata, DistributionDatabase}; use uv_distribution_types::{ BuiltDist, CompatibleDist, Dist, DistributionMetadata, IncompatibleDist, IncompatibleSource, IncompatibleWheel, IndexCapabilities, IndexLocations, IndexUrl, InstalledDist, PythonRequirementKind, RemoteSource, ResolvedDist, ResolvedDistRef, SourceDist, VersionOrUrlRef, }; use uv_git::GitResolver; use uv_normalize::{ExtraName, GroupName, PackageName}; use uv_pep440::{release_specifiers_to_ranges, Version, MIN_VERSION}; use uv_pep508::MarkerTree; use uv_platform_tags::Tags; use uv_pypi_types::{ ConflictItem, ConflictItemRef, Conflicts, Requirement, ResolutionMetadata, VerbatimParsedUrl, }; use uv_types::{BuildContext, HashStrategy, InstalledPackagesProvider}; use uv_warnings::warn_user_once; use crate::candidate_selector::{CandidateDist, CandidateSelector}; use crate::dependency_provider::UvDependencyProvider; use crate::error::{NoSolutionError, ResolveError}; use crate::fork_indexes::ForkIndexes; use crate::fork_urls::ForkUrls; use crate::manifest::Manifest; use crate::pins::FilePins; use crate::preferences::Preferences; use crate::pubgrub::{ PubGrubDependency, PubGrubDistribution, PubGrubPackage, PubGrubPackageInner, PubGrubPriorities, PubGrubPython, }; use crate::python_requirement::PythonRequirement; use crate::resolution::ResolutionGraph; use crate::resolution_mode::ResolutionStrategy; pub(crate) use crate::resolver::availability::{ IncompletePackage, ResolverVersion, UnavailablePackage, UnavailableReason, UnavailableVersion, }; use crate::resolver::batch_prefetch::BatchPrefetcher; use crate::resolver::groups::Groups; pub use crate::resolver::index::InMemoryIndex; use crate::resolver::indexes::Indexes; pub use crate::resolver::provider::{ DefaultResolverProvider, MetadataResponse, PackageVersionsResult, ResolverProvider, VersionsResponse, WheelMetadataResult, }; use crate::resolver::reporter::Facade; pub use crate::resolver::reporter::{BuildId, Reporter}; use crate::yanks::AllowedYanks; use crate::{marker, DependencyMode, Exclusions, FlatIndex, Options, ResolutionMode}; mod availability; mod batch_prefetch; mod environment; mod fork_map; mod groups; mod index; mod indexes; mod provider; mod reporter; mod urls; pub struct Resolver { state: ResolverState, provider: Provider, } /// State that is shared between the prefetcher and the PubGrub solver during /// resolution, across all forks. struct ResolverState { project: Option, requirements: Vec, constraints: Constraints, overrides: Overrides, groups: Groups, preferences: Preferences, git: GitResolver, capabilities: IndexCapabilities, locations: IndexLocations, exclusions: Exclusions, urls: Urls, indexes: Indexes, dependency_mode: DependencyMode, hasher: HashStrategy, env: ResolverEnvironment, python_requirement: PythonRequirement, conflicts: Conflicts, workspace_members: BTreeSet, selector: CandidateSelector, index: InMemoryIndex, installed_packages: InstalledPackages, /// Incompatibilities for packages that are entirely unavailable. unavailable_packages: DashMap, /// Incompatibilities for packages that are unavailable at specific versions. incomplete_packages: DashMap>, /// The options that were used to configure this resolver. options: Options, /// The reporter to use for this resolver. reporter: Option>, } impl<'a, Context: BuildContext, InstalledPackages: InstalledPackagesProvider> Resolver, InstalledPackages> { /// Initialize a new resolver using the default backend doing real requests. /// /// Reads the flat index entries. /// /// # Marker environment /// /// The marker environment is optional. /// /// When a marker environment is not provided, the resolver is said to be /// in "universal" mode. When in universal mode, the resolution produced /// may contain multiple versions of the same package. And thus, in order /// to use the resulting resolution, there must be a "universal"-aware /// reader of the resolution that knows to exclude distributions that can't /// be used in the current environment. /// /// When a marker environment is provided, the resolver is in /// "non-universal" mode, which corresponds to standard `pip` behavior that /// works only for a specific marker environment. pub fn new( manifest: Manifest, options: Options, python_requirement: &'a PythonRequirement, env: ResolverEnvironment, conflicts: Conflicts, tags: Option<&'a Tags>, flat_index: &'a FlatIndex, index: &'a InMemoryIndex, hasher: &'a HashStrategy, build_context: &'a Context, installed_packages: InstalledPackages, database: DistributionDatabase<'a, Context>, ) -> Result { let provider = DefaultResolverProvider::new( database, flat_index, tags, python_requirement.target(), AllowedYanks::from_manifest(&manifest, &env, options.dependency_mode), hasher, options.exclude_newer, build_context.build_options(), build_context.capabilities(), ); Self::new_custom_io( manifest, options, hasher, env, python_requirement, conflicts, index, build_context.git(), build_context.capabilities(), build_context.locations(), provider, installed_packages, ) } } impl Resolver { /// Initialize a new resolver using a user provided backend. pub fn new_custom_io( manifest: Manifest, options: Options, hasher: &HashStrategy, env: ResolverEnvironment, python_requirement: &PythonRequirement, conflicts: Conflicts, index: &InMemoryIndex, git: &GitResolver, capabilities: &IndexCapabilities, locations: &IndexLocations, provider: Provider, installed_packages: InstalledPackages, ) -> Result { let state = ResolverState { index: index.clone(), git: git.clone(), capabilities: capabilities.clone(), selector: CandidateSelector::for_resolution(options, &manifest, &env), dependency_mode: options.dependency_mode, urls: Urls::from_manifest(&manifest, &env, git, options.dependency_mode)?, indexes: Indexes::from_manifest(&manifest, &env, options.dependency_mode), groups: Groups::from_manifest(&manifest, &env), project: manifest.project, workspace_members: manifest.workspace_members, requirements: manifest.requirements, constraints: manifest.constraints, overrides: manifest.overrides, preferences: manifest.preferences, exclusions: manifest.exclusions, hasher: hasher.clone(), locations: locations.clone(), env, python_requirement: python_requirement.clone(), conflicts, installed_packages, unavailable_packages: DashMap::default(), incomplete_packages: DashMap::default(), options, reporter: None, }; Ok(Self { state, provider }) } /// Set the [`Reporter`] to use for this installer. #[must_use] pub fn with_reporter(self, reporter: impl Reporter + 'static) -> Self { let reporter = Arc::new(reporter); Self { state: ResolverState { reporter: Some(reporter.clone()), ..self.state }, provider: self.provider.with_reporter(Facade { reporter }), } } /// Resolve a set of requirements into a set of pinned versions. pub async fn resolve(self) -> Result { let state = Arc::new(self.state); let provider = Arc::new(self.provider); // A channel to fetch package metadata (e.g., given `flask`, fetch all versions) and version // metadata (e.g., given `flask==1.0.0`, fetch the metadata for that version). // Channel size is set large to accommodate batch prefetching. let (request_sink, request_stream) = mpsc::channel(300); // Run the fetcher. let requests_fut = state.clone().fetch(provider.clone(), request_stream).fuse(); // Spawn the PubGrub solver on a dedicated thread. let solver = state.clone(); let (tx, rx) = oneshot::channel(); thread::Builder::new() .name("uv-resolver".into()) .spawn(move || { let result = solver.solve(request_sink); // This may fail if the main thread returned early due to an error. let _ = tx.send(result); }) .unwrap(); let resolve_fut = async move { rx.await.map_err(|_| ResolveError::ChannelClosed) }; // Wait for both to complete. let ((), resolution) = tokio::try_join!(requests_fut, resolve_fut)?; state.on_complete(); resolution } } impl ResolverState { #[instrument(skip_all)] fn solve( self: Arc, request_sink: Sender, ) -> Result { debug!( "Solving with installed Python version: {}", self.python_requirement.exact() ); debug!( "Solving with target Python version: {}", self.python_requirement.target() ); let mut visited = FxHashSet::default(); let root = PubGrubPackage::from(PubGrubPackageInner::Root(self.project.clone())); let mut prefetcher = BatchPrefetcher::default(); let state = ForkState::new( State::init(root.clone(), MIN_VERSION.clone()), root, self.env.clone(), self.python_requirement.clone(), ); let mut preferences = self.preferences.clone(); let mut forked_states = self.env.initial_forked_states(state); let mut resolutions = vec![]; 'FORK: while let Some(mut state) = forked_states.pop() { if let Some(split) = state.env.end_user_fork_display() { let requires_python = state.python_requirement.target(); debug!("Solving {split} (requires-python: {requires_python:?})"); } let start = Instant::now(); loop { // Run unit propagation. if let Err(err) = state.pubgrub.unit_propagation(state.next.clone()) { return Err(self.convert_no_solution_err( err, state.fork_urls, &state.fork_indexes, state.env, &visited, &self.locations, &self.capabilities, )); } // Pre-visit all candidate packages, to allow metadata to be fetched in parallel. if self.dependency_mode.is_transitive() { Self::pre_visit( state.pubgrub.partial_solution.prioritized_packages(), &self.urls, &self.indexes, &state.python_requirement, &request_sink, )?; } // Choose a package version. let Some(highest_priority_pkg) = state .pubgrub .partial_solution .pick_highest_priority_pkg(|package, _range| state.priorities.get(package)) else { if tracing::enabled!(Level::DEBUG) { prefetcher.log_tried_versions(); } debug!( "{} resolution took {:.3}s", state.env, start.elapsed().as_secs_f32() ); let resolution = state.into_resolution(); // Walk over the selected versions, and mark them as preferences. We have to // add forks back as to not override the preferences from the lockfile for // the next fork // // If we're using a resolution mode that varies based on whether a dependency is // direct or transitive, skip preferences, as we risk adding a preference from // one fork (in which it's a transitive dependency) to another fork (in which // it's direct). if matches!( self.options.resolution_mode, ResolutionMode::Lowest | ResolutionMode::Highest ) { for (package, version) in &resolution.nodes { preferences.insert( package.name.clone(), resolution.env.try_markers().cloned(), version.clone(), ); } } resolutions.push(resolution); continue 'FORK; }; state.next = highest_priority_pkg; let url = state.next.name().and_then(|name| state.fork_urls.get(name)); let index = state .next .name() .and_then(|name| state.fork_indexes.get(name)); // Consider: // ```toml // dependencies = [ // "iniconfig == 1.1.1 ; python_version < '3.12'", // "iniconfig @ https://files.pythonhosted.org/packages/ef/a6/62565a6e1cf69e10f5727360368e451d4b7f58beeac6173dc9db836a5b46/iniconfig-2.0.0-py3-none-any.whl ; python_version >= '3.12'", // ] // ``` // In the `python_version < '3.12'` case, we haven't pre-visited `iniconfig` yet, // since we weren't sure whether it might also be a URL requirement when // transforming the requirements. For that case, we do another request here // (idempotent due to caching). self.request_package(&state.next, url, index, &request_sink)?; prefetcher.version_tried(state.next.clone()); let term_intersection = state .pubgrub .partial_solution .term_intersection_for_package(&state.next) .expect("a package was chosen but we don't have a term"); let decision = self.choose_version( &state.next, index, term_intersection.unwrap_positive(), &mut state.pins, &preferences, &state.fork_urls, &state.env, &state.python_requirement, &mut visited, &request_sink, )?; // Pick the next compatible version. let version = match decision { None => { debug!("No compatible version found for: {next}", next = state.next); let term_intersection = state .pubgrub .partial_solution .term_intersection_for_package(&state.next) .expect("a package was chosen but we don't have a term"); if let PubGrubPackageInner::Package { ref name, .. } = &*state.next { // Check if the decision was due to the package being unavailable if let Some(entry) = self.unavailable_packages.get(name) { state .pubgrub .add_incompatibility(Incompatibility::custom_term( state.next.clone(), term_intersection.clone(), UnavailableReason::Package(entry.clone()), )); continue; } } state .pubgrub .add_incompatibility(Incompatibility::no_versions( state.next.clone(), term_intersection.clone(), )); continue; } Some(version) => version, }; let version = match version { ResolverVersion::Available(version) => version, ResolverVersion::Unavailable(version, reason) => { state.add_unavailable_version(version, reason); continue; } }; // Only consider registry packages for prefetch. if url.is_none() { prefetcher.prefetch_batches( &state.next, index, &version, term_intersection.unwrap_positive(), state .pubgrub .partial_solution .unchanging_term_for_package(&state.next), &state.python_requirement, &request_sink, &self.index, &self.capabilities, &self.selector, &state.env, )?; } self.on_progress(&state.next, &version); if !state .added_dependencies .entry(state.next.clone()) .or_default() .insert(version.clone()) { // `dep_incompats` are already in `incompatibilities` so we know there are not satisfied // terms and can add the decision directly. state .pubgrub .partial_solution .add_decision(state.next.clone(), version); continue; } let for_package = if let PubGrubPackageInner::Root(_) = &*state.next { None } else { state.next.name().map(|name| format!("{name}=={version}")) }; // Retrieve that package dependencies. let forked_deps = self.get_dependencies_forking( &state.next, &version, &state.fork_urls, &state.env, &state.python_requirement, )?; match forked_deps { ForkedDependencies::Unavailable(reason) => { state .pubgrub .add_incompatibility(Incompatibility::custom_version( state.next.clone(), version.clone(), UnavailableReason::Version(reason), )); } ForkedDependencies::Unforked(dependencies) => { state.add_package_version_dependencies( for_package.as_deref(), &version, &self.urls, &self.indexes, dependencies.clone(), &self.git, self.selector.resolution_strategy(), )?; // Emit a request to fetch the metadata for each registry package. for dependency in &dependencies { let PubGrubDependency { package, version: _, specifier: _, url: _, } = dependency; let url = package.name().and_then(|name| state.fork_urls.get(name)); let index = package.name().and_then(|name| state.fork_indexes.get(name)); self.visit_package(package, url, index, &request_sink)?; } } ForkedDependencies::Forked { forks, diverging_packages, } => { debug!( "Pre-fork {} took {:.3}s", state.env, start.elapsed().as_secs_f32() ); for new_fork_state in self.forks_to_fork_states( state, &version, forks, &request_sink, for_package.as_deref(), &diverging_packages, ) { forked_states.push(new_fork_state?); } continue 'FORK; } } } } if resolutions.len() > 1 { info!( "Solved your requirements for {} environments", resolutions.len() ); } for resolution in &resolutions { if let Some(env) = resolution.env.end_user_fork_display() { debug!( "Distinct solution for {env} with {} packages", resolution.nodes.len() ); } } for resolution in &resolutions { Self::trace_resolution(resolution); } ResolutionGraph::from_state( &resolutions, &self.requirements, &self.constraints, &self.overrides, &self.preferences, &self.index, &self.git, &self.python_requirement, &self.conflicts, self.selector.resolution_strategy(), self.options, ) } /// When trace level logging is enabled, we dump the final /// set of resolutions, including markers, to help with /// debugging. Namely, this tells use precisely the state /// emitted by the resolver before going off to construct a /// resolution graph. fn trace_resolution(combined: &Resolution) { if !tracing::enabled!(Level::TRACE) { return; } trace!("Resolution: {:?}", combined.env); for edge in &combined.edges { trace!( "Resolution edge: {} -> {}", edge.from .as_ref() .map(PackageName::as_str) .unwrap_or("ROOT"), edge.to, ); // The unwraps below are OK because `write`ing to // a String can never fail (except for OOM). let mut msg = String::new(); write!(msg, "{}", edge.from_version).unwrap(); if let Some(ref extra) = edge.from_extra { write!(msg, " (extra: {extra})").unwrap(); } if let Some(ref dev) = edge.from_dev { write!(msg, " (group: {dev})").unwrap(); } write!(msg, " -> ").unwrap(); write!(msg, "{}", edge.to_version).unwrap(); if let Some(ref extra) = edge.to_extra { write!(msg, " (extra: {extra})").unwrap(); } if let Some(ref dev) = edge.to_dev { write!(msg, " (group: {dev})").unwrap(); } if let Some(marker) = edge.marker.contents() { write!(msg, " ; {marker}").unwrap(); } trace!("Resolution edge: {msg}"); } } /// Convert the dependency [`Fork`]s into [`ForkState`]s. fn forks_to_fork_states<'a>( &'a self, current_state: ForkState, version: &'a Version, forks: Vec, request_sink: &'a Sender, for_package: Option<&'a str>, diverging_packages: &'a [PackageName], ) -> impl Iterator> + 'a { debug!( "Splitting resolution on {}=={} over {} into {} resolution with separate markers", current_state.next, version, diverging_packages .iter() .map(ToString::to_string) .join(", "), forks.len() ); assert!(forks.len() >= 2); // This is a somewhat tortured technique to ensure // that our resolver state is only cloned as much // as it needs to be. We basically move the state // into `forked_states`, and then only clone it if // there is at least one more fork to visit. let mut cur_state = Some(current_state); let forks_len = forks.len(); forks .into_iter() .enumerate() .map(move |(i, fork)| { let is_last = i == forks_len - 1; let forked_state = cur_state.take().unwrap(); if !is_last { cur_state = Some(forked_state.clone()); } let env = fork.env.clone(); (fork, forked_state.with_env(env)) }) .map(move |(fork, mut forked_state)| { forked_state.add_package_version_dependencies( for_package, version, &self.urls, &self.indexes, fork.dependencies.clone(), &self.git, self.selector.resolution_strategy(), )?; // Emit a request to fetch the metadata for each registry package. for dependency in &fork.dependencies { let PubGrubDependency { package, version: _, specifier: _, url: _, } = dependency; let url = package .name() .and_then(|name| forked_state.fork_urls.get(name)); let index = package .name() .and_then(|name| forked_state.fork_indexes.get(name)); self.visit_package(package, url, index, request_sink)?; } Ok(forked_state) }) } /// Visit a [`PubGrubPackage`] prior to selection. This should be called on a [`PubGrubPackage`] /// before it is selected, to allow metadata to be fetched in parallel. fn visit_package( &self, package: &PubGrubPackage, url: Option<&VerbatimParsedUrl>, index: Option<&IndexUrl>, request_sink: &Sender, ) -> Result<(), ResolveError> { // Ignore unresolved URL packages. if url.is_none() && package .name() .map(|name| self.urls.any_url(name)) .unwrap_or(true) { return Ok(()); } self.request_package(package, url, index, request_sink) } fn request_package( &self, package: &PubGrubPackage, url: Option<&VerbatimParsedUrl>, index: Option<&IndexUrl>, request_sink: &Sender, ) -> Result<(), ResolveError> { // Only request real package let Some(name) = package.name_no_root() else { return Ok(()); }; if let Some(url) = url { // Verify that the package is allowed under the hash-checking policy. if !self.hasher.allows_url(&url.verbatim) { return Err(ResolveError::UnhashedPackage(name.clone())); } // Emit a request to fetch the metadata for this distribution. let dist = Dist::from_url(name.clone(), url.clone())?; if self.index.distributions().register(dist.version_id()) { request_sink.blocking_send(Request::Dist(dist))?; } } else if let Some(index) = index { // Emit a request to fetch the metadata for this package on the index. if self .index .explicit() .register((name.clone(), index.clone())) { request_sink.blocking_send(Request::Package(name.clone(), Some(index.clone())))?; } } else { // Emit a request to fetch the metadata for this package. if self.index.implicit().register(name.clone()) { request_sink.blocking_send(Request::Package(name.clone(), None))?; } } Ok(()) } /// Visit the set of [`PubGrubPackage`] candidates prior to selection. This allows us to fetch /// metadata for all packages in parallel. fn pre_visit<'data>( packages: impl Iterator)>, urls: &Urls, indexes: &Indexes, python_requirement: &PythonRequirement, request_sink: &Sender, ) -> Result<(), ResolveError> { // Iterate over the potential packages, and fetch file metadata for any of them. These // represent our current best guesses for the versions that we _might_ select. for (package, range) in packages { let PubGrubPackageInner::Package { name, extra: None, dev: None, marker: None, } = &**package else { continue; }; // Avoid pre-visiting packages that have any URLs in any fork. At this point we can't // tell whether they are registry distributions or which url they use. if urls.any_url(name) { continue; } // Avoid visiting packages that may use an explicit index. if indexes.contains_key(name) { continue; } request_sink.blocking_send(Request::Prefetch( name.clone(), range.clone(), python_requirement.clone(), ))?; } Ok(()) } /// Given a candidate package, choose the next version in range to try. /// /// Returns `None` when there are no versions in the given range, rejecting the current partial /// solution. #[instrument(skip_all, fields(%package))] fn choose_version( &self, package: &PubGrubPackage, index: Option<&IndexUrl>, range: &Range, pins: &mut FilePins, preferences: &Preferences, fork_urls: &ForkUrls, env: &ResolverEnvironment, python_requirement: &PythonRequirement, visited: &mut FxHashSet, request_sink: &Sender, ) -> Result, ResolveError> { match &**package { PubGrubPackageInner::Root(_) => { Ok(Some(ResolverVersion::Available(MIN_VERSION.clone()))) } PubGrubPackageInner::Python(_) => { // Dependencies on Python are only added when a package is incompatible; as such, // we don't need to do anything here. // we don't need to do anything here. Ok(None) } PubGrubPackageInner::Marker { name, .. } | PubGrubPackageInner::Extra { name, .. } | PubGrubPackageInner::Dev { name, .. } | PubGrubPackageInner::Package { name, .. } => { if let Some(url) = package.name().and_then(|name| fork_urls.get(name)) { self.choose_version_url(name, range, url, python_requirement) } else { self.choose_version_registry( name, index, range, package, preferences, env, python_requirement, pins, visited, request_sink, ) } } } } /// Select a version for a URL requirement. Since there is only one version per URL, we return /// that version if it is in range and `None` otherwise. fn choose_version_url( &self, name: &PackageName, range: &Range, url: &VerbatimParsedUrl, python_requirement: &PythonRequirement, ) -> Result, ResolveError> { debug!( "Searching for a compatible version of {name} @ {} ({range})", url.verbatim ); let dist = PubGrubDistribution::from_url(name, url); let response = self .index .distributions() .wait_blocking(&dist.version_id()) .ok_or_else(|| ResolveError::UnregisteredTask(dist.version_id().to_string()))?; // If we failed to fetch the metadata for a URL, we can't proceed. let metadata = match &*response { MetadataResponse::Found(archive) => &archive.metadata, MetadataResponse::Offline => { self.unavailable_packages .insert(name.clone(), UnavailablePackage::Offline); return Ok(None); } MetadataResponse::MissingMetadata => { self.unavailable_packages .insert(name.clone(), UnavailablePackage::MissingMetadata); return Ok(None); } MetadataResponse::InvalidMetadata(err) => { self.unavailable_packages.insert( name.clone(), UnavailablePackage::InvalidMetadata(err.to_string()), ); return Ok(None); } MetadataResponse::InconsistentMetadata(err) => { self.unavailable_packages.insert( name.clone(), UnavailablePackage::InvalidMetadata(err.to_string()), ); return Ok(None); } MetadataResponse::InvalidStructure(err) => { self.unavailable_packages.insert( name.clone(), UnavailablePackage::InvalidStructure(err.to_string()), ); return Ok(None); } MetadataResponse::RequiresPython(..) => { unreachable!("`requires-python` is only known upfront for registry distributions") } MetadataResponse::Error(dist, err) => { return Err(match &**dist { Dist::Built(built_dist @ BuiltDist::Path(_)) => { ResolveError::Read(Box::new(built_dist.clone()), (*err).clone()) } Dist::Source(source_dist @ SourceDist::Path(_)) => { ResolveError::Build(Box::new(source_dist.clone()), (*err).clone()) } Dist::Source(source_dist @ SourceDist::Directory(_)) => { ResolveError::Build(Box::new(source_dist.clone()), (*err).clone()) } Dist::Built(built_dist) => { ResolveError::Download(Box::new(built_dist.clone()), (*err).clone()) } Dist::Source(source_dist) => { if source_dist.is_local() { ResolveError::Build(Box::new(source_dist.clone()), (*err).clone()) } else { ResolveError::DownloadAndBuild( Box::new(source_dist.clone()), (*err).clone(), ) } } }); } }; let version = &metadata.version; // The version is incompatible with the requirement. if !range.contains(version) { return Ok(None); } // The version is incompatible due to its Python requirement. if let Some(requires_python) = metadata.requires_python.as_ref() { if !python_requirement .installed() .is_contained_by(requires_python) { return Ok(Some(ResolverVersion::Unavailable( version.clone(), UnavailableVersion::IncompatibleDist(IncompatibleDist::Source( IncompatibleSource::RequiresPython( requires_python.clone(), PythonRequirementKind::Installed, ), )), ))); } if !python_requirement.target().is_contained_by(requires_python) { return Ok(Some(ResolverVersion::Unavailable( version.clone(), UnavailableVersion::IncompatibleDist(IncompatibleDist::Source( IncompatibleSource::RequiresPython( requires_python.clone(), PythonRequirementKind::Target, ), )), ))); } } Ok(Some(ResolverVersion::Available(version.clone()))) } /// Given a candidate registry requirement, choose the next version in range to try, or `None` /// if there is no version in this range. fn choose_version_registry( &self, name: &PackageName, index: Option<&IndexUrl>, range: &Range, package: &PubGrubPackage, preferences: &Preferences, env: &ResolverEnvironment, python_requirement: &PythonRequirement, pins: &mut FilePins, visited: &mut FxHashSet, request_sink: &Sender, ) -> Result, ResolveError> { // Wait for the metadata to be available. let versions_response = if let Some(index) = index { self.index .explicit() .wait_blocking(&(name.clone(), index.clone())) .ok_or_else(|| ResolveError::UnregisteredTask(name.to_string()))? } else { self.index .implicit() .wait_blocking(name) .ok_or_else(|| ResolveError::UnregisteredTask(name.to_string()))? }; visited.insert(name.clone()); let version_maps = match *versions_response { VersionsResponse::Found(ref version_maps) => version_maps.as_slice(), VersionsResponse::NoIndex => { self.unavailable_packages .insert(name.clone(), UnavailablePackage::NoIndex); &[] } VersionsResponse::Offline => { self.unavailable_packages .insert(name.clone(), UnavailablePackage::Offline); &[] } VersionsResponse::NotFound => { self.unavailable_packages .insert(name.clone(), UnavailablePackage::NotFound); &[] } }; debug!("Searching for a compatible version of {package} ({range})"); // Find a version. let Some(candidate) = self.selector.select( name, range, version_maps, preferences, &self.installed_packages, &self.exclusions, env, ) else { // Short circuit: we couldn't find _any_ versions for a package. return Ok(None); }; let dist = match candidate.dist() { CandidateDist::Compatible(dist) => dist, CandidateDist::Incompatible(incompatibility) => { // If the version is incompatible because no distributions are compatible, exit early. return Ok(Some(ResolverVersion::Unavailable( candidate.version().clone(), UnavailableVersion::IncompatibleDist(incompatibility.clone()), ))); } }; // Validate the Python requirement. let requires_python = match dist { CompatibleDist::InstalledDist(_) => None, CompatibleDist::SourceDist { sdist, .. } | CompatibleDist::IncompatibleWheel { sdist, .. } => { sdist.file.requires_python.as_ref() } CompatibleDist::CompatibleWheel { wheel, .. } => wheel.file.requires_python.as_ref(), }; let incompatibility = requires_python.and_then(|requires_python| { if python_requirement.installed() == python_requirement.target() { if !python_requirement .installed() .is_contained_by(requires_python) { return if matches!(dist, CompatibleDist::CompatibleWheel { .. }) { Some(IncompatibleDist::Wheel(IncompatibleWheel::RequiresPython( requires_python.clone(), PythonRequirementKind::Installed, ))) } else { Some(IncompatibleDist::Source( IncompatibleSource::RequiresPython( requires_python.clone(), PythonRequirementKind::Installed, ), )) }; } } else { if !python_requirement.target().is_contained_by(requires_python) { return if matches!(dist, CompatibleDist::CompatibleWheel { .. }) { Some(IncompatibleDist::Wheel(IncompatibleWheel::RequiresPython( requires_python.clone(), PythonRequirementKind::Target, ))) } else { Some(IncompatibleDist::Source( IncompatibleSource::RequiresPython( requires_python.clone(), PythonRequirementKind::Target, ), )) }; } } None }); // The version is incompatible due to its Python requirement. if let Some(incompatibility) = incompatibility { return Ok(Some(ResolverVersion::Unavailable( candidate.version().clone(), UnavailableVersion::IncompatibleDist(incompatibility), ))); } let filename = match dist.for_installation() { ResolvedDistRef::InstallableRegistrySourceDist { sdist, .. } => sdist .filename() .unwrap_or(Cow::Borrowed("unknown filename")), ResolvedDistRef::InstallableRegistryBuiltDist { wheel, .. } => wheel .filename() .unwrap_or(Cow::Borrowed("unknown filename")), ResolvedDistRef::Installed { .. } => Cow::Borrowed("installed"), }; debug!( "Selecting: {}=={} [{}] ({})", name, candidate.version(), candidate.choice_kind(), filename, ); // We want to return a package pinned to a specific version; but we _also_ want to // store the exact file that we selected to satisfy that version. pins.insert(&candidate, dist); let version = candidate.version().clone(); // Emit a request to fetch the metadata for this version. if matches!(&**package, PubGrubPackageInner::Package { .. }) { if self.dependency_mode.is_transitive() { if self.index.distributions().register(candidate.version_id()) { // Verify that the package is allowed under the hash-checking policy. if !self .hasher .allows_package(candidate.name(), candidate.version()) { return Err(ResolveError::UnhashedPackage(candidate.name().clone())); } let request = Request::from(dist.for_resolution()); request_sink.blocking_send(request)?; } } } Ok(Some(ResolverVersion::Available(version))) } /// Given a candidate package and version, return its dependencies. #[instrument(skip_all, fields(%package, %version))] fn get_dependencies_forking( &self, package: &PubGrubPackage, version: &Version, fork_urls: &ForkUrls, env: &ResolverEnvironment, python_requirement: &PythonRequirement, ) -> Result { let result = self.get_dependencies(package, version, fork_urls, env, python_requirement); if env.marker_environment().is_some() { result.map(|deps| match deps { Dependencies::Available(deps) | Dependencies::Unforkable(deps) => { ForkedDependencies::Unforked(deps) } Dependencies::Unavailable(err) => ForkedDependencies::Unavailable(err), }) } else { Ok(result?.fork(env, python_requirement, &self.conflicts)) } } /// Given a candidate package and version, return its dependencies. #[instrument(skip_all, fields(%package, %version))] fn get_dependencies( &self, package: &PubGrubPackage, version: &Version, fork_urls: &ForkUrls, env: &ResolverEnvironment, python_requirement: &PythonRequirement, ) -> Result { let url = package.name().and_then(|name| fork_urls.get(name)); let dependencies = match &**package { PubGrubPackageInner::Root(_) => { let no_dev_deps = BTreeMap::default(); let requirements = self.flatten_requirements( &self.requirements, &no_dev_deps, None, None, None, env, python_requirement, ); requirements .iter() .flat_map(|requirement| PubGrubDependency::from_requirement(requirement, None)) .collect() } PubGrubPackageInner::Package { name, extra, dev, marker, } => { // If we're excluding transitive dependencies, short-circuit. if self.dependency_mode.is_direct() { return Ok(Dependencies::Unforkable(Vec::default())); } // Determine the distribution to lookup. let dist = match url { Some(url) => PubGrubDistribution::from_url(name, url), None => PubGrubDistribution::from_registry(name, version), }; let version_id = dist.version_id(); // If the package does not exist in the registry or locally, we cannot fetch its dependencies if self.dependency_mode.is_transitive() && self.unavailable_packages.get(name).is_some() && self.installed_packages.get_packages(name).is_empty() { debug_assert!( false, "Dependencies were requested for a package that is not available" ); return Err(ResolveError::PackageUnavailable(name.clone())); } // Wait for the metadata to be available. let response = self .index .distributions() .wait_blocking(&version_id) .ok_or_else(|| ResolveError::UnregisteredTask(version_id.to_string()))?; let metadata = match &*response { MetadataResponse::Found(archive) => &archive.metadata, MetadataResponse::Offline => { self.incomplete_packages .entry(name.clone()) .or_default() .insert(version.clone(), IncompletePackage::Offline); return Ok(Dependencies::Unavailable(UnavailableVersion::Offline)); } MetadataResponse::MissingMetadata => { self.incomplete_packages .entry(name.clone()) .or_default() .insert(version.clone(), IncompletePackage::MissingMetadata); return Ok(Dependencies::Unavailable( UnavailableVersion::MissingMetadata, )); } MetadataResponse::InvalidMetadata(err) => { warn!("Unable to extract metadata for {name}: {err}"); self.incomplete_packages .entry(name.clone()) .or_default() .insert( version.clone(), IncompletePackage::InvalidMetadata(err.to_string()), ); return Ok(Dependencies::Unavailable( UnavailableVersion::InvalidMetadata, )); } MetadataResponse::InconsistentMetadata(err) => { warn!("Unable to extract metadata for {name}: {err}"); self.incomplete_packages .entry(name.clone()) .or_default() .insert( version.clone(), IncompletePackage::InconsistentMetadata(err.to_string()), ); return Ok(Dependencies::Unavailable( UnavailableVersion::InconsistentMetadata, )); } MetadataResponse::InvalidStructure(err) => { warn!("Unable to extract metadata for {name}: {err}"); self.incomplete_packages .entry(name.clone()) .or_default() .insert( version.clone(), IncompletePackage::InvalidStructure(err.to_string()), ); return Ok(Dependencies::Unavailable( UnavailableVersion::InvalidStructure, )); } MetadataResponse::RequiresPython(requires_python, python_version) => { warn!( "Unable to extract metadata for {name}: {}", uv_distribution::Error::RequiresPython( requires_python.clone(), python_version.clone() ) ); self.incomplete_packages .entry(name.clone()) .or_default() .insert( version.clone(), IncompletePackage::RequiresPython( requires_python.clone(), python_version.clone(), ), ); return Ok(Dependencies::Unavailable( UnavailableVersion::RequiresPython(requires_python.clone()), )); } MetadataResponse::Error(dist, err) => { return Err(match &**dist { Dist::Built(built_dist @ BuiltDist::Path(_)) => { ResolveError::Read(Box::new(built_dist.clone()), (*err).clone()) } Dist::Source(source_dist @ SourceDist::Path(_)) => { ResolveError::Build(Box::new(source_dist.clone()), (*err).clone()) } Dist::Source(source_dist @ SourceDist::Directory(_)) => { ResolveError::Build(Box::new(source_dist.clone()), (*err).clone()) } Dist::Built(built_dist) => { ResolveError::Download(Box::new(built_dist.clone()), (*err).clone()) } Dist::Source(source_dist) => { if source_dist.is_local() { ResolveError::Build( Box::new(source_dist.clone()), (*err).clone(), ) } else { ResolveError::DownloadAndBuild( Box::new(source_dist.clone()), (*err).clone(), ) } } }); } }; if let Some(err) = find_conflicting_extra(&self.conflicts, &metadata.requires_dist) { return Err(err); } for dependencies in metadata.dependency_groups.values() { if let Some(err) = find_conflicting_extra(&self.conflicts, dependencies) { return Err(err); } } let requirements = self.flatten_requirements( &metadata.requires_dist, &metadata.dependency_groups, extra.as_ref(), dev.as_ref(), Some(name), env, python_requirement, ); let mut dependencies: Vec<_> = requirements .iter() .flat_map(|requirement| { PubGrubDependency::from_requirement(requirement, Some(name)) }) .collect(); // If a package has metadata for an enabled dependency group, // add a dependency from it to the same package with the group // enabled. if extra.is_none() && dev.is_none() { for group in self.groups.get(name).into_iter().flatten() { if !metadata.dependency_groups.contains_key(group) { continue; } dependencies.push(PubGrubDependency { package: PubGrubPackage::from(PubGrubPackageInner::Dev { name: name.clone(), dev: group.clone(), marker: marker.clone(), }), version: Range::singleton(version.clone()), specifier: None, url: None, }); } } dependencies } PubGrubPackageInner::Python(_) => return Ok(Dependencies::Unforkable(Vec::default())), // Add a dependency on both the marker and base package. PubGrubPackageInner::Marker { name, marker } => { return Ok(Dependencies::Unforkable( [None, Some(marker)] .into_iter() .map(move |marker| PubGrubDependency { package: PubGrubPackage::from(PubGrubPackageInner::Package { name: name.clone(), extra: None, dev: None, marker: marker.and_then(MarkerTree::contents), }), version: Range::singleton(version.clone()), specifier: None, url: None, }) .collect(), )) } // Add a dependency on both the extra and base package, with and without the marker. PubGrubPackageInner::Extra { name, extra, marker, } => { return Ok(Dependencies::Unforkable( [None, marker.as_ref()] .into_iter() .dedup() .flat_map(move |marker| { [None, Some(extra)] .into_iter() .map(move |extra| PubGrubDependency { package: PubGrubPackage::from(PubGrubPackageInner::Package { name: name.clone(), extra: extra.cloned(), dev: None, marker: marker.cloned(), }), version: Range::singleton(version.clone()), specifier: None, url: None, }) }) .collect(), )) } // Add a dependency on both the development dependency group and base package, with and // without the marker. PubGrubPackageInner::Dev { name, dev, marker } => { return Ok(Dependencies::Unforkable( [None, marker.as_ref()] .into_iter() .dedup() .flat_map(move |marker| { [None, Some(dev)] .into_iter() .map(move |dev| PubGrubDependency { package: PubGrubPackage::from(PubGrubPackageInner::Package { name: name.clone(), extra: None, dev: dev.cloned(), marker: marker.cloned(), }), version: Range::singleton(version.clone()), specifier: None, url: None, }) }) .collect(), )) } }; Ok(Dependencies::Available(dependencies)) } /// The regular and dev dependencies filtered by Python version and the markers of this fork, /// plus the extras dependencies of the current package (e.g., `black` depending on /// `black[colorama]`). fn flatten_requirements<'a>( &'a self, dependencies: &'a [Requirement], dev_dependencies: &'a BTreeMap>, extra: Option<&'a ExtraName>, dev: Option<&'a GroupName>, name: Option<&PackageName>, env: &'a ResolverEnvironment, python_requirement: &'a PythonRequirement, ) -> Vec> { // Start with the requirements for the current extra of the package (for an extra // requirement) or the non-extra (regular) dependencies (if extra is None), plus // the constraints for the current package. let regular_and_dev_dependencies = if let Some(dev) = dev { Either::Left(dev_dependencies.get(dev).into_iter().flatten()) } else { Either::Right(dependencies.iter()) }; let mut requirements = self .requirements_for_extra(regular_and_dev_dependencies, extra, env, python_requirement) .collect::>(); // Check if there are recursive self inclusions and we need to go into the expensive branch. if !requirements .iter() .any(|req| name == Some(&req.name) && !req.extras.is_empty()) { return requirements; } // Transitively process all extras that are recursively included, starting with the current // extra. let mut seen = FxHashSet::default(); let mut queue: VecDeque<_> = requirements .iter() .filter(|req| name == Some(&req.name)) .flat_map(|req| req.extras.iter().cloned()) .collect(); while let Some(extra) = queue.pop_front() { if !seen.insert(extra.clone()) { continue; } for requirement in self.requirements_for_extra(dependencies, Some(&extra), env, python_requirement) { if name == Some(&requirement.name) { // Add each transitively included extra. queue.extend(requirement.extras.iter().cloned()); } else { // Add the requirements for that extra. requirements.push(requirement); } } } // Drop all the self-requirements now that we flattened them out. requirements.retain(|req| name != Some(&req.name)); requirements } /// The set of the regular and dev dependencies, filtered by Python version, /// the markers of this fork and the requested extra. fn requirements_for_extra<'data, 'parameters>( &'data self, dependencies: impl IntoIterator + 'parameters, extra: Option<&'parameters ExtraName>, env: &'parameters ResolverEnvironment, python_requirement: &'parameters PythonRequirement, ) -> impl Iterator> + 'parameters where 'data: 'parameters, { self.overrides .apply(dependencies) .filter_map(move |requirement| { let python_marker = python_requirement.to_marker_tree(); // If the requirement would not be selected with any Python version // supported by the root, skip it. if python_marker.is_disjoint(&requirement.marker) { trace!( "skipping {requirement} because of Requires-Python: {requires_python}", requires_python = python_requirement.target(), ); return None; } // If we're in a fork in universal mode, ignore any dependency that isn't part of // this fork (but will be part of another fork). if !env.included_by_marker(&requirement.marker) { trace!("skipping {requirement} because of {env}"); return None; } // If the requirement isn't relevant for the current platform, skip it. match extra { Some(source_extra) => { // Only include requirements that are relevant for the current extra. if requirement.evaluate_markers(env.marker_environment(), &[]) { return None; } if !requirement.evaluate_markers( env.marker_environment(), std::slice::from_ref(source_extra), ) { return None; } if !env.included_by_group( ConflictItemRef::from((&requirement.name, source_extra)), ) { return None; } } None => { if !requirement.evaluate_markers(env.marker_environment(), &[]) { return None; } } } Some(requirement) }) .flat_map(move |requirement| { iter::once(requirement.clone()).chain( self.constraints .get(&requirement.name) .into_iter() .flatten() .filter_map(move |constraint| { // If the requirement would not be selected with any Python version // supported by the root, skip it. let constraint = if constraint.marker.is_true() { // Additionally, if the requirement is `requests ; sys_platform == 'darwin'` // and the constraint is `requests ; python_version == '3.6'`, the // constraint should only apply when _both_ markers are true. if requirement.marker.is_true() { Cow::Borrowed(constraint) } else { let mut marker = constraint.marker.clone(); marker.and(requirement.marker.clone()); Cow::Owned(Requirement { name: constraint.name.clone(), extras: constraint.extras.clone(), source: constraint.source.clone(), origin: constraint.origin.clone(), marker, }) } } else { let requires_python = python_requirement.target(); let python_marker = python_requirement.to_marker_tree(); let mut marker = constraint.marker.clone(); marker.and(requirement.marker.clone()); // Additionally, if the requirement is `requests ; sys_platform == 'darwin'` // and the constraint is `requests ; python_version == '3.6'`, the // constraint should only apply when _both_ markers are true. if marker.is_false() { trace!("skipping {constraint} because of Requires-Python: {requires_python}"); return None; } if python_marker.is_disjoint(&marker) { trace!( "skipping constraint {requirement} because of Requires-Python: {requires_python}", requires_python = python_requirement.target(), ); return None; } if marker == constraint.marker { Cow::Borrowed(constraint) } else { Cow::Owned(Requirement { name: constraint.name.clone(), extras: constraint.extras.clone(), source: constraint.source.clone(), origin: constraint.origin.clone(), marker, }) } }; // If we're in a fork in universal mode, ignore any dependency that isn't part of // this fork (but will be part of another fork). if !env.included_by_marker(&constraint.marker) { trace!("skipping {constraint} because of {env}"); return None; } // If the constraint isn't relevant for the current platform, skip it. match extra { Some(source_extra) => { if !constraint.evaluate_markers( env.marker_environment(), std::slice::from_ref(source_extra), ) { return None; } if !env.included_by_group( ConflictItemRef::from((&requirement.name, source_extra)), ) { return None; } } None => { if !constraint.evaluate_markers(env.marker_environment(), &[]) { return None; } } } Some(constraint) }) ) }) } /// Fetch the metadata for a stream of packages and versions. async fn fetch( self: Arc, provider: Arc, request_stream: Receiver, ) -> Result<(), ResolveError> { let mut response_stream = ReceiverStream::new(request_stream) .map(|request| self.process_request(request, &*provider).boxed_local()) // Allow as many futures as possible to start in the background. // Backpressure is provided by at a more granular level by `DistributionDatabase` // and `SourceDispatch`, as well as the bounded request channel. .buffer_unordered(usize::MAX); while let Some(response) = response_stream.next().await { match response? { Some(Response::Package(name, index, version_map)) => { trace!("Received package metadata for: {name}"); if let Some(index) = index { self.index .explicit() .done((name, index), Arc::new(version_map)); } else { self.index.implicit().done(name, Arc::new(version_map)); } } Some(Response::Installed { dist, metadata }) => { trace!("Received installed distribution metadata for: {dist}"); self.index.distributions().done( dist.version_id(), Arc::new(MetadataResponse::Found(ArchiveMetadata::from_metadata23( metadata, ))), ); } Some(Response::Dist { dist: Dist::Built(dist), metadata, }) => { trace!("Received built distribution metadata for: {dist}"); match &metadata { MetadataResponse::InvalidMetadata(err) => { warn!("Unable to extract metadata for {dist}: {err}"); } MetadataResponse::InvalidStructure(err) => { warn!("Unable to extract metadata for {dist}: {err}"); } _ => {} } self.index .distributions() .done(dist.version_id(), Arc::new(metadata)); } Some(Response::Dist { dist: Dist::Source(dist), metadata, }) => { trace!("Received source distribution metadata for: {dist}"); match &metadata { MetadataResponse::InvalidMetadata(err) => { warn!("Unable to extract metadata for {dist}: {err}"); } MetadataResponse::InvalidStructure(err) => { warn!("Unable to extract metadata for {dist}: {err}"); } _ => {} } self.index .distributions() .done(dist.version_id(), Arc::new(metadata)); } None => {} } } Ok::<(), ResolveError>(()) } #[instrument(skip_all, fields(%request))] async fn process_request( &self, request: Request, provider: &Provider, ) -> Result, ResolveError> { match request { // Fetch package metadata from the registry. Request::Package(package_name, index) => { let package_versions = provider .get_package_versions(&package_name, index.as_ref()) .boxed_local() .await .map_err(ResolveError::Client)?; Ok(Some(Response::Package( package_name, index, package_versions, ))) } // Fetch distribution metadata from the distribution database. Request::Dist(dist) => { let metadata = provider .get_or_build_wheel_metadata(&dist) .boxed_local() .await?; Ok(Some(Response::Dist { dist, metadata })) } Request::Installed(dist) => { let metadata = dist .metadata() .map_err(|err| ResolveError::ReadInstalled(Box::new(dist.clone()), err))?; Ok(Some(Response::Installed { dist, metadata })) } // Pre-fetch the package and distribution metadata. Request::Prefetch(package_name, range, python_requirement) => { // Wait for the package metadata to become available. let versions_response = self .index .implicit() .wait(&package_name) .await .ok_or_else(|| ResolveError::UnregisteredTask(package_name.to_string()))?; let version_map = match *versions_response { VersionsResponse::Found(ref version_map) => version_map, // Short-circuit if we did not find any versions for the package VersionsResponse::NoIndex => { self.unavailable_packages .insert(package_name.clone(), UnavailablePackage::NoIndex); return Ok(None); } VersionsResponse::Offline => { self.unavailable_packages .insert(package_name.clone(), UnavailablePackage::Offline); return Ok(None); } VersionsResponse::NotFound => { self.unavailable_packages .insert(package_name.clone(), UnavailablePackage::NotFound); return Ok(None); } }; // We don't have access to the fork state when prefetching, so assume that // pre-release versions are allowed. let env = ResolverEnvironment::universal(vec![]); // Try to find a compatible version. If there aren't any compatible versions, // short-circuit. let Some(candidate) = self.selector.select( &package_name, &range, version_map, &self.preferences, &self.installed_packages, &self.exclusions, &env, ) else { return Ok(None); }; // If there is not a compatible distribution, short-circuit. let Some(dist) = candidate.compatible() else { return Ok(None); }; // Avoid prefetching source distributions with unbounded lower-bound ranges. This // often leads to failed attempts to build legacy versions of packages that are // incompatible with modern build tools. if dist.wheel().is_none() { if !self.selector.use_highest_version(&package_name, &env) { if let Some((lower, _)) = range.iter().next() { if lower == &Bound::Unbounded { debug!("Skipping prefetch for unbounded minimum-version range: {package_name} ({range})"); return Ok(None); } } } } // Validate the Python requirement. let requires_python = match dist { CompatibleDist::InstalledDist(_) => None, CompatibleDist::SourceDist { sdist, .. } | CompatibleDist::IncompatibleWheel { sdist, .. } => { sdist.file.requires_python.as_ref() } CompatibleDist::CompatibleWheel { wheel, .. } => { wheel.file.requires_python.as_ref() } }; if let Some(requires_python) = requires_python.as_ref() { if !python_requirement.target().is_contained_by(requires_python) { return Ok(None); } } // Emit a request to fetch the metadata for this version. if self.index.distributions().register(candidate.version_id()) { // Verify that the package is allowed under the hash-checking policy. if !self .hasher .allows_package(candidate.name(), candidate.version()) { return Err(ResolveError::UnhashedPackage(candidate.name().clone())); } let dist = dist.for_resolution().to_owned(); let response = match dist { ResolvedDist::Installable { dist, .. } => { let metadata = provider .get_or_build_wheel_metadata(&dist) .boxed_local() .await?; Response::Dist { dist, metadata } } ResolvedDist::Installed { dist } => { let metadata = dist.metadata().map_err(|err| { ResolveError::ReadInstalled(Box::new(dist.clone()), err) })?; Response::Installed { dist, metadata } } }; Ok(Some(response)) } else { Ok(None) } } } } fn convert_no_solution_err( &self, mut err: pubgrub::NoSolutionError, fork_urls: ForkUrls, fork_indexes: &ForkIndexes, env: ResolverEnvironment, visited: &FxHashSet, index_locations: &IndexLocations, index_capabilities: &IndexCapabilities, ) -> ResolveError { err = NoSolutionError::collapse_local_version_segments(NoSolutionError::collapse_proxies( err, )); let mut unavailable_packages = FxHashMap::default(); for package in err.packages() { if let PubGrubPackageInner::Package { name, .. } = &**package { if let Some(reason) = self.unavailable_packages.get(name) { unavailable_packages.insert(name.clone(), reason.clone()); } } } let mut incomplete_packages = FxHashMap::default(); for package in err.packages() { if let PubGrubPackageInner::Package { name, .. } = &**package { if let Some(versions) = self.incomplete_packages.get(name) { for entry in versions.iter() { let (version, reason) = entry.pair(); incomplete_packages .entry(name.clone()) .or_insert_with(BTreeMap::default) .insert(version.clone(), reason.clone()); } } } } let mut available_indexes = FxHashMap::default(); let mut available_versions = FxHashMap::default(); for package in err.packages() { let Some(name) = package.name() else { continue }; if !visited.contains(name) { // Avoid including available versions for packages that exist in the derivation // tree, but were never visited during resolution. We _may_ have metadata for // these packages, but it's non-deterministic, and omitting them ensures that // we represent the self of the resolver at the time of failure. continue; } let versions_response = if let Some(index) = fork_indexes.get(name) { self.index.explicit().get(&(name.clone(), index.clone())) } else { self.index.implicit().get(name) }; if let Some(response) = versions_response { if let VersionsResponse::Found(ref version_maps) = *response { // Track the available versions, across all indexes. for version_map in version_maps { available_versions .entry(name.clone()) .or_insert_with(BTreeSet::new) .extend(version_map.versions().cloned()); } // Track the indexes in which the package is available. available_indexes .entry(name.clone()) .or_insert(BTreeSet::new()) .extend( version_maps .iter() .filter_map(|version_map| version_map.index().cloned()), ); } } } ResolveError::NoSolution(NoSolutionError::new( err, available_versions, available_indexes, self.selector.clone(), self.python_requirement.clone(), index_locations.clone(), index_capabilities.clone(), unavailable_packages, incomplete_packages, fork_urls, env, self.workspace_members.clone(), self.options, )) } fn on_progress(&self, package: &PubGrubPackage, version: &Version) { if let Some(reporter) = self.reporter.as_ref() { match &**package { PubGrubPackageInner::Root(_) => {} PubGrubPackageInner::Python(_) => {} PubGrubPackageInner::Marker { .. } => {} PubGrubPackageInner::Extra { .. } => {} PubGrubPackageInner::Dev { .. } => {} PubGrubPackageInner::Package { name, .. } => { reporter.on_progress(name, &VersionOrUrlRef::Version(version)); } } } } fn on_complete(&self) { if let Some(reporter) = self.reporter.as_ref() { reporter.on_complete(); } } } /// State that is used during unit propagation in the resolver, one instance per fork. #[derive(Clone)] pub(crate) struct ForkState { /// The internal state used by the resolver. /// /// Note that not all parts of this state are strictly internal. For /// example, the edges in the dependency graph generated as part of the /// output of resolution are derived from the "incompatibilities" tracked /// in this state. We also ultimately retrieve the final set of version /// assignments (to packages) from this state's "partial solution." pubgrub: State, /// The next package on which to run unit propagation. next: PubGrubPackage, /// The set of pinned versions we accrue throughout resolution. /// /// The key of this map is a package name, and each package name maps to /// a set of versions for that package. Each version in turn is mapped /// to a single [`ResolvedDist`]. That [`ResolvedDist`] represents, at time /// of writing (2024/05/09), at most one wheel. The idea here is that /// [`FilePins`] tracks precisely which wheel was selected during resolution. /// After resolution is finished, this maps is consulted in order to select /// the wheel chosen during resolution. pins: FilePins, /// Ensure we don't have duplicate URLs in any branch. /// /// Unlike [`Urls`], we add only the URLs we have seen in this branch, and there can be only /// one URL per package. By prioritizing direct URL dependencies over registry dependencies, /// this map is populated for all direct URL packages before we look at any registry packages. fork_urls: ForkUrls, /// Ensure we don't have duplicate indexes in any branch. /// /// Unlike [`Indexes`], we add only the indexes we have seen in this branch, and there can be /// only one index per package. fork_indexes: ForkIndexes, /// When dependencies for a package are retrieved, this map of priorities /// is updated based on how each dependency was specified. Certain types /// of dependencies have more "priority" than others (like direct URL /// dependencies). These priorities help determine which package to /// consider next during resolution. priorities: PubGrubPriorities, /// This keeps track of the set of versions for each package that we've /// already visited during resolution. This avoids doing redundant work. added_dependencies: FxHashMap>, /// The marker expression that created this state. /// /// The root state always corresponds to a marker expression that is always /// `true` for every `MarkerEnvironment`. /// /// In non-universal mode, forking never occurs and so this marker /// expression is always `true`. /// /// Whenever dependencies are fetched, all requirement specifications /// are checked for disjointness with the marker expression of the fork /// in which those dependencies were fetched. If a requirement has a /// completely disjoint marker expression (i.e., it can never be true given /// that the marker expression that provoked the fork is true), then that /// dependency is completely ignored. env: ResolverEnvironment, /// The Python requirement for this fork. Defaults to the Python requirement for /// the resolution, but may be narrowed if a `python_version` marker is present /// in a given fork. /// /// For example, in: /// ```text /// numpy >=1.26 ; python_version >= "3.9" /// numpy <1.26 ; python_version < "3.9" /// ``` /// /// The top fork has a narrower Python compatibility range, and thus can find a /// solution that omits Python 3.8 support. python_requirement: PythonRequirement, } impl ForkState { fn new( pubgrub: State, root: PubGrubPackage, env: ResolverEnvironment, python_requirement: PythonRequirement, ) -> Self { Self { pubgrub, next: root, pins: FilePins::default(), fork_urls: ForkUrls::default(), fork_indexes: ForkIndexes::default(), priorities: PubGrubPriorities::default(), added_dependencies: FxHashMap::default(), env, python_requirement, } } /// Add the dependencies for the selected version of the current package, checking for /// self-dependencies and handling URLs. fn add_package_version_dependencies( &mut self, for_package: Option<&str>, version: &Version, urls: &Urls, indexes: &Indexes, mut dependencies: Vec, git: &GitResolver, resolution_strategy: &ResolutionStrategy, ) -> Result<(), ResolveError> { for dependency in &mut dependencies { let PubGrubDependency { package, version, url, .. } = dependency; let mut has_url = false; if let Some(name) = package.name() { // From the [`Requirement`] to [`PubGrubDependency`] conversion, we get a URL if the // requirement was a URL requirement. `Urls` applies canonicalization to this and // override URLs to both URL and registry requirements, which we then check for // conflicts using [`ForkUrl`]. if let Some(url) = urls.get_url(&self.env, name, url.as_ref(), git)? { self.fork_urls.insert(name, url, &self.env)?; has_url = true; }; // If the package is pinned to an exact index, add it to the fork. for index in indexes.get(name, &self.env) { self.fork_indexes.insert(name, index, &self.env)?; } } if let Some(for_package) = for_package { debug!("Adding transitive dependency for {for_package}: {package}{version}"); } else { // A dependency from the root package or requirements.txt. debug!("Adding direct dependency: {package}{version}"); // Warn the user if a direct dependency lacks a lower bound in `--lowest` resolution. let missing_lower_bound = version .bounding_range() .map(|(lowest, _highest)| lowest == Bound::Unbounded) .unwrap_or(true); let strategy_lowest = matches!( resolution_strategy, ResolutionStrategy::Lowest | ResolutionStrategy::LowestDirect(..) ); if !has_url && missing_lower_bound && strategy_lowest { warn_user_once!( "The direct dependency `{package}` is unpinned. \ Consider setting a lower bound when using `--resolution lowest` \ to avoid using outdated versions." ); } } // Update the package priorities. self.priorities.insert(package, version, &self.fork_urls); } self.pubgrub.add_package_version_dependencies( self.next.clone(), version.clone(), dependencies.into_iter().map(|dependency| { let PubGrubDependency { package, version, specifier: _, url: _, } = dependency; (package, version) }), ); Ok(()) } fn add_unavailable_version(&mut self, version: Version, reason: UnavailableVersion) { // Incompatible requires-python versions are special in that we track // them as incompatible dependencies instead of marking the package version // as unavailable directly. if let UnavailableVersion::IncompatibleDist( IncompatibleDist::Source(IncompatibleSource::RequiresPython(requires_python, kind)) | IncompatibleDist::Wheel(IncompatibleWheel::RequiresPython(requires_python, kind)), ) = reason { let package = &self.next; self.pubgrub .add_incompatibility(Incompatibility::from_dependency( package.clone(), Range::singleton(version.clone()), ( PubGrubPackage::from(PubGrubPackageInner::Python(match kind { PythonRequirementKind::Installed => PubGrubPython::Installed, PythonRequirementKind::Target => PubGrubPython::Target, })), release_specifiers_to_ranges(requires_python), ), )); self.pubgrub .partial_solution .add_decision(self.next.clone(), version); return; }; self.pubgrub .add_incompatibility(Incompatibility::custom_version( self.next.clone(), version.clone(), UnavailableReason::Version(reason), )); } /// Subset the current markers with the new markers and update the python requirements fields /// accordingly. /// /// If the fork should be dropped (e.g., because its markers can never be true for its /// Python requirement), then this returns `None`. fn with_env(mut self, env: ResolverEnvironment) -> Self { self.env = env; // If the fork contains a narrowed Python requirement, apply it. if let Some(req) = self.env.narrow_python_requirement(&self.python_requirement) { debug!("Narrowed `requires-python` bound to: {}", req.target()); self.python_requirement = req; } self } fn into_resolution(self) -> Resolution { let solution = self.pubgrub.partial_solution.extract_solution(); let mut edges: FxHashSet = FxHashSet::default(); for (package, self_version) in &solution { for id in &self.pubgrub.incompatibilities[package] { let pubgrub::Kind::FromDependencyOf( ref self_package, ref self_range, ref dependency_package, ref dependency_range, ) = self.pubgrub.incompatibility_store[*id].kind else { continue; }; if package != self_package { continue; } if !self_range.contains(self_version) { continue; } let Some(dependency_version) = solution.get(dependency_package) else { continue; }; if !dependency_range.contains(dependency_version) { continue; } let (self_name, self_extra, self_dev) = match &**self_package { PubGrubPackageInner::Package { name: self_name, extra: self_extra, dev: self_dev, .. } => (Some(self_name), self_extra.as_ref(), self_dev.as_ref()), PubGrubPackageInner::Root(_) => (None, None, None), _ => continue, }; let self_url = self_name.as_ref().and_then(|name| self.fork_urls.get(name)); let self_index = self_name .as_ref() .and_then(|name| self.fork_indexes.get(name)); match **dependency_package { PubGrubPackageInner::Package { name: ref dependency_name, extra: ref dependency_extra, dev: ref dependency_dev, .. } => { if self_name.is_some_and(|self_name| self_name == dependency_name) { continue; } let to_url = self.fork_urls.get(dependency_name); let to_index = self.fork_indexes.get(dependency_name); let edge = ResolutionDependencyEdge { from: self_name.cloned(), from_version: self_version.clone(), from_url: self_url.cloned(), from_index: self_index.cloned(), from_extra: self_extra.cloned(), from_dev: self_dev.cloned(), to: dependency_name.clone(), to_version: dependency_version.clone(), to_url: to_url.cloned(), to_index: to_index.cloned(), to_extra: dependency_extra.clone(), to_dev: dependency_dev.clone(), marker: MarkerTree::TRUE, }; edges.insert(edge); } PubGrubPackageInner::Marker { name: ref dependency_name, marker: ref dependency_marker, .. } => { if self_name.is_some_and(|self_name| self_name == dependency_name) { continue; } let to_url = self.fork_urls.get(dependency_name); let to_index = self.fork_indexes.get(dependency_name); let edge = ResolutionDependencyEdge { from: self_name.cloned(), from_version: self_version.clone(), from_url: self_url.cloned(), from_index: self_index.cloned(), from_extra: self_extra.cloned(), from_dev: self_dev.cloned(), to: dependency_name.clone(), to_version: dependency_version.clone(), to_url: to_url.cloned(), to_index: to_index.cloned(), to_extra: None, to_dev: None, marker: dependency_marker.clone(), }; edges.insert(edge); } PubGrubPackageInner::Extra { name: ref dependency_name, extra: ref dependency_extra, marker: ref dependency_marker, .. } => { if self_name.is_some_and(|self_name| self_name == dependency_name) { continue; } let to_url = self.fork_urls.get(dependency_name); let to_index = self.fork_indexes.get(dependency_name); let edge = ResolutionDependencyEdge { from: self_name.cloned(), from_version: self_version.clone(), from_url: self_url.cloned(), from_index: self_index.cloned(), from_extra: self_extra.cloned(), from_dev: self_dev.cloned(), to: dependency_name.clone(), to_version: dependency_version.clone(), to_url: to_url.cloned(), to_index: to_index.cloned(), to_extra: Some(dependency_extra.clone()), to_dev: None, marker: MarkerTree::from(dependency_marker.clone()), }; edges.insert(edge); } PubGrubPackageInner::Dev { name: ref dependency_name, dev: ref dependency_dev, marker: ref dependency_marker, .. } => { if self_name.is_some_and(|self_name| self_name == dependency_name) { continue; } let to_url = self.fork_urls.get(dependency_name); let to_index = self.fork_indexes.get(dependency_name); let edge = ResolutionDependencyEdge { from: self_name.cloned(), from_version: self_version.clone(), from_url: self_url.cloned(), from_index: self_index.cloned(), from_extra: self_extra.cloned(), from_dev: self_dev.cloned(), to: dependency_name.clone(), to_version: dependency_version.clone(), to_url: to_url.cloned(), to_index: to_index.cloned(), to_extra: None, to_dev: Some(dependency_dev.clone()), marker: MarkerTree::from(dependency_marker.clone()), }; edges.insert(edge); } _ => {} } } } let nodes = solution .into_iter() .filter_map(|(package, version)| { if let PubGrubPackageInner::Package { name, extra, dev, marker: None, } = &*package { Some(( ResolutionPackage { name: name.clone(), extra: extra.clone(), dev: dev.clone(), url: self.fork_urls.get(name).cloned(), index: self.fork_indexes.get(name).cloned(), }, version, )) } else { None } }) .collect(); Resolution { nodes, edges, pins: self.pins, env: self.env, } } } /// The resolution from a single fork including the virtual packages and the edges between them. #[derive(Debug)] pub(crate) struct Resolution { pub(crate) nodes: FxHashMap, /// The directed connections between the nodes, where the marker is the node weight. We don't /// store the requirement itself, but it can be retrieved from the package metadata. pub(crate) edges: FxHashSet, /// Map each package name, version tuple from `packages` to a distribution. pub(crate) pins: FilePins, /// The environment setting this resolution was found under. pub(crate) env: ResolverEnvironment, } /// Package representation we used during resolution where each extra and also the dev-dependencies /// group are their own package. #[derive(Clone, Debug, Eq, Hash, PartialEq)] pub(crate) struct ResolutionPackage { pub(crate) name: PackageName, pub(crate) extra: Option, pub(crate) dev: Option, /// For index packages, this is `None`. pub(crate) url: Option, /// For URL packages, this is `None`, and is only `Some` for packages that are pinned to a /// specific index via `tool.uv.sources`. pub(crate) index: Option, } /// The `from_` fields and the `to_` fields allow mapping to the originating and target /// [`ResolutionPackage`] respectively. The `marker` is the edge weight. #[derive(Clone, Debug, Eq, Hash, PartialEq)] pub(crate) struct ResolutionDependencyEdge { /// This value is `None` if the dependency comes from the root package. pub(crate) from: Option, pub(crate) from_version: Version, pub(crate) from_url: Option, pub(crate) from_index: Option, pub(crate) from_extra: Option, pub(crate) from_dev: Option, pub(crate) to: PackageName, pub(crate) to_version: Version, pub(crate) to_url: Option, pub(crate) to_index: Option, pub(crate) to_extra: Option, pub(crate) to_dev: Option, pub(crate) marker: MarkerTree, } impl ResolutionPackage { pub(crate) fn is_base(&self) -> bool { self.extra.is_none() && self.dev.is_none() } } /// Fetch the metadata for an item #[derive(Debug)] #[allow(clippy::large_enum_variant)] pub(crate) enum Request { /// A request to fetch the metadata for a package. Package(PackageName, Option), /// A request to fetch the metadata for a built or source distribution. Dist(Dist), /// A request to fetch the metadata from an already-installed distribution. Installed(InstalledDist), /// A request to pre-fetch the metadata for a package and the best-guess distribution. Prefetch(PackageName, Range, PythonRequirement), } impl<'a> From> for Request { fn from(dist: ResolvedDistRef<'a>) -> Request { // N.B. This is almost identical to `ResolvedDistRef::to_owned`, but // creates a `Request` instead of a `ResolvedDist`. There's probably // some room for DRYing this up a bit. The obvious way would be to // add a method to create a `Dist`, but a `Dist` cannot be represented // as an installed dist. match dist { ResolvedDistRef::InstallableRegistrySourceDist { sdist, prioritized } => { // This is okay because we're only here if the prioritized dist // has an sdist, so this always succeeds. let source = prioritized.source_dist().expect("a source distribution"); assert_eq!( (&sdist.name, &sdist.version), (&source.name, &source.version), "expected chosen sdist to match prioritized sdist" ); Request::Dist(Dist::Source(SourceDist::Registry(source))) } ResolvedDistRef::InstallableRegistryBuiltDist { wheel, prioritized, .. } => { assert_eq!( Some(&wheel.filename), prioritized.best_wheel().map(|(wheel, _)| &wheel.filename), "expected chosen wheel to match best wheel" ); // This is okay because we're only here if the prioritized dist // has at least one wheel, so this always succeeds. let built = prioritized.built_dist().expect("at least one wheel"); Request::Dist(Dist::Built(BuiltDist::Registry(built))) } ResolvedDistRef::Installed { dist } => Request::Installed(dist.clone()), } } } impl Display for Request { fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result { match self { Self::Package(package_name, _) => { write!(f, "Versions {package_name}") } Self::Dist(dist) => { write!(f, "Metadata {dist}") } Self::Installed(dist) => { write!(f, "Installed metadata {dist}") } Self::Prefetch(package_name, range, _) => { write!(f, "Prefetch {package_name} {range}") } } } } #[derive(Debug)] #[allow(clippy::large_enum_variant)] enum Response { /// The returned metadata for a package hosted on a registry. Package(PackageName, Option, VersionsResponse), /// The returned metadata for a distribution. Dist { dist: Dist, metadata: MetadataResponse, }, /// The returned metadata for an already-installed distribution. Installed { dist: InstalledDist, metadata: ResolutionMetadata, }, } /// Information about the dependencies for a particular package. /// /// This effectively distills the dependency metadata of a package down into /// its pubgrub specific constituent parts: each dependency package has a range /// of possible versions. enum Dependencies { /// Package dependencies are not available. Unavailable(UnavailableVersion), /// Container for all available package versions. /// /// Note that in universal mode, it is possible and allowed for multiple /// `PubGrubPackage` values in this list to have the same package name. /// These conflicts are resolved via `Dependencies::fork`. Available(Vec), /// Dependencies that should never result in a fork. /// /// For example, the dependencies of a `Marker` package will have the /// same name and version, but differ according to marker expressions. /// But we never want this to result in a fork. Unforkable(Vec), } impl Dependencies { /// Turn this flat list of dependencies into a potential set of forked /// groups of dependencies. /// /// A fork *only* occurs when there are multiple dependencies with the same /// name *and* those dependency specifications have corresponding marker /// expressions that are completely disjoint with one another. fn fork( self, env: &ResolverEnvironment, python_requirement: &PythonRequirement, conflicts: &Conflicts, ) -> ForkedDependencies { let deps = match self { Dependencies::Available(deps) => deps, Dependencies::Unforkable(deps) => return ForkedDependencies::Unforked(deps), Dependencies::Unavailable(err) => return ForkedDependencies::Unavailable(err), }; let mut name_to_deps: BTreeMap> = BTreeMap::new(); for dep in deps { let name = dep .package .name() .expect("dependency always has a name") .clone(); name_to_deps.entry(name).or_default().push(dep); } let Forks { mut forks, diverging_packages, } = Forks::new(name_to_deps, env, python_requirement, conflicts); if forks.is_empty() { ForkedDependencies::Unforked(vec![]) } else if forks.len() == 1 { ForkedDependencies::Unforked(forks.pop().unwrap().dependencies) } else { // Prioritize the forks. Prefer solving forks with lower Python // bounds, since they're more likely to produce solutions that work // for forks with higher Python bounds (whereas the inverse is not // true). forks.sort(); ForkedDependencies::Forked { forks, diverging_packages: diverging_packages.into_iter().collect(), } } } } /// Information about the (possibly forked) dependencies for a particular /// package. /// /// This is like `Dependencies` but with an extra variant that only occurs when /// a `Dependencies` list has multiple dependency specifications with the same /// name and non-overlapping marker expressions (i.e., a fork occurs). #[derive(Debug)] enum ForkedDependencies { /// Package dependencies are not available. Unavailable(UnavailableVersion), /// No forking occurred. /// /// This is the same as `Dependencies::Available`. Unforked(Vec), /// Forked containers for all available package versions. /// /// Note that there is always at least two forks. If there would /// be fewer than 2 forks, then there is no fork at all and the /// `Unforked` variant is used instead. Forked { forks: Vec, /// The package(s) with different requirements for disjoint markers. diverging_packages: Vec, }, } /// A list of forks determined from the dependencies of a single package. /// /// Any time a marker expression is seen that is not true for all possible /// marker environments, it is possible for it to introduce a new fork. #[derive(Debug, Default)] struct Forks { /// The forks discovered among the dependencies. forks: Vec, /// The package(s) that provoked at least one additional fork. diverging_packages: BTreeSet, } impl Forks { fn new( name_to_deps: BTreeMap>, env: &ResolverEnvironment, python_requirement: &PythonRequirement, conflicts: &Conflicts, ) -> Forks { let python_marker = python_requirement.to_marker_tree(); let mut forks = vec![Fork::new(env.clone())]; let mut diverging_packages = BTreeSet::new(); for (name, mut deps) in name_to_deps { assert!(!deps.is_empty(), "every name has at least one dependency"); // We never fork if there's only one dependency // specification for a given package name. This particular // strategy results in a "conservative" approach to forking // that gives up correctness in some cases in exchange for // more limited forking. More limited forking results in // simpler-and-easier-to-understand lock files and faster // resolving. The correctness we give up manifests when // two transitive non-sibling dependencies conflict. In // that case, we don't detect the fork ahead of time (at // present). if let [dep] = deps.as_slice() { // There's one exception: if the requirement increases the minimum-supported Python // version, we also fork in order to respect that minimum in the subsequent // resolution. // // For example, given `requires-python = ">=3.7"` and `uv ; python_version >= "3.8"`, // where uv itself only supports Python 3.8 and later, we need to fork to ensure // that the resolution can find a solution. if !dep .package .marker() .and_then(marker::requires_python) .is_some_and(|bound| python_requirement.raises(&bound)) { let dep = deps.pop().unwrap(); let markers = dep.package.marker().cloned().unwrap_or(MarkerTree::TRUE); for fork in &mut forks { if fork.env.included_by_marker(&markers) { fork.add_dependency(dep.clone()); } } continue; } } for dep in deps { let mut forker = match ForkingPossibility::new(env, &dep) { ForkingPossibility::Possible(forker) => forker, ForkingPossibility::DependencyAlwaysExcluded => { // If the markers can never be satisfied by the parent // fork, then we can drop this dependency unceremoniously. continue; } ForkingPossibility::NoForkingPossible => { // Or, if the markers are always true, then we just // add the dependency to every fork unconditionally. for fork in &mut forks { fork.add_dependency(dep.clone()); } continue; } }; // Otherwise, we *should* need to add a new fork... diverging_packages.insert(name.clone()); let mut new = vec![]; for fork in std::mem::take(&mut forks) { let Some((remaining_forker, envs)) = forker.fork(&fork.env) else { new.push(fork); continue; }; forker = remaining_forker; for fork_env in envs { let mut new_fork = fork.clone(); new_fork.set_env(fork_env); // We only add the dependency to this fork if it // satisfies the fork's markers. Some forks are // specifically created to exclude this dependency, // so this isn't always true! if forker.included(&new_fork.env) { new_fork.add_dependency(dep.clone()); } // Filter out any forks we created that are disjoint with our // Python requirement. if new_fork.env.included_by_marker(&python_marker) { new.push(new_fork); } } } forks = new; } } // When there is a conflicting group configuration, we need // to potentially add more forks. Each fork added contains an // exclusion list of conflicting groups where dependencies with // the corresponding package and extra name are forcefully // excluded from that group. // // We specifically iterate on conflicting groups and // potentially re-generate all forks for each one. We do it // this way in case there are multiple sets of conflicting // groups that impact the forks here. // // For example, if we have conflicting groups {x1, x2} and {x3, // x4}, we need to make sure the forks generated from one set // also account for the other set. for set in conflicts.iter() { let mut new = vec![]; for fork in std::mem::take(&mut forks) { let mut has_conflicting_dependency = false; for item in set.iter() { if fork.contains_conflicting_item(item.as_ref()) { has_conflicting_dependency = true; diverging_packages.insert(item.package().clone()); break; } } if !has_conflicting_dependency { new.push(fork); continue; } // Create a fork that excludes ALL extras. let mut fork_none = fork.clone(); for group in set.iter() { fork_none = fork_none.exclude([group.clone()]); } new.push(fork_none); // Now create a fork for each conflicting group, where // that fork excludes every *other* conflicting group. // // So if we have conflicting extras foo, bar and baz, // then this creates three forks: one that excludes // {foo, bar}, one that excludes {foo, baz} and one // that excludes {bar, baz}. for (i, _) in set.iter().enumerate() { let fork_allows_group = fork.clone().exclude( set.iter() .enumerate() .filter(|&(j, _)| i != j) .map(|(_, group)| group.clone()), ); new.push(fork_allows_group); } } forks = new; } Forks { forks, diverging_packages, } } } /// A single fork in a list of dependencies. /// /// A fork corresponds to the full list of dependencies for a package, /// but with any conflicting dependency specifications omitted. For /// example, if we have `a<2 ; sys_platform == 'foo'` and `a>=2 ; /// sys_platform == 'bar'`, then because the dependency specifications /// have the same name and because the marker expressions are disjoint, /// a fork occurs. One fork will contain `a<2` but not `a>=2`, while /// the other fork will contain `a>=2` but not `a<2`. #[derive(Clone, Debug)] struct Fork { /// The list of dependencies for this fork, guaranteed to be conflict /// free. (i.e., There are no two packages with the same name with /// non-overlapping marker expressions.) /// /// Note that callers shouldn't mutate this sequence directly. Instead, /// they should use `add_forked_package` or `add_nonfork_package`. Namely, /// it should be impossible for a package with a marker expression that is /// disjoint from the marker expression on this fork to be added. dependencies: Vec, /// The conflicting groups in this fork. /// /// This exists to make some access patterns more efficient. Namely, /// it makes it easy to check whether there's a dependency with a /// particular conflicting group in this fork. conflicts: crate::FxHashbrownSet, /// The resolver environment for this fork. /// /// Principally, this corresponds to the markers in this for. So in the /// example above, the `a<2` fork would have `sys_platform == 'foo'`, while /// the `a>=2` fork would have `sys_platform == 'bar'`. /// /// If this fork was generated from another fork, then this *includes* /// the criteria from its parent. i.e., Its marker expression represents /// the intersection of the marker expression from its parent and any /// additional marker expression generated by addition forking based on /// conflicting dependency specifications. env: ResolverEnvironment, } impl Fork { /// Create a new fork with no dependencies with the given resolver /// environment. fn new(env: ResolverEnvironment) -> Fork { Fork { dependencies: vec![], conflicts: crate::FxHashbrownSet::default(), env, } } /// Add a dependency to this fork. fn add_dependency(&mut self, dep: PubGrubDependency) { if let Some(conflicting_item) = dep.package.conflicting_item() { self.conflicts.insert(conflicting_item.to_owned()); } self.dependencies.push(dep); } /// Sets the resolver environment to the one given. /// /// Any dependency in this fork that does not satisfy the given environment /// is removed. fn set_env(&mut self, env: ResolverEnvironment) { self.env = env; self.dependencies.retain(|dep| { let Some(markers) = dep.package.marker() else { return true; }; if self.env.included_by_marker(markers) { return true; } if let Some(conflicting_item) = dep.package.conflicting_item() { self.conflicts.remove(&conflicting_item); } false }); } /// Returns true if any of the dependencies in this fork contain a /// dependency with the given package and extra values. fn contains_conflicting_item(&self, item: ConflictItemRef<'_>) -> bool { self.conflicts.contains(&item) } /// Exclude the given groups from this fork. /// /// This removes all dependencies matching the given conflicting groups. fn exclude(mut self, groups: impl IntoIterator) -> Fork { self.env = self.env.exclude_by_group(groups); self.dependencies.retain(|dep| { let Some(conflicting_item) = dep.package.conflicting_item() else { return true; }; if self.env.included_by_group(conflicting_item) { return true; } if let Some(conflicting_item) = dep.package.conflicting_item() { self.conflicts.remove(&conflicting_item); } false }); self } } impl Eq for Fork {} impl PartialEq for Fork { fn eq(&self, other: &Fork) -> bool { self.dependencies == other.dependencies && self.env == other.env } } impl Ord for Fork { fn cmp(&self, other: &Self) -> Ordering { // A higher `requires-python` requirement indicates a _lower-priority_ fork. We'd prefer // to solve `<3.7` before solving `>=3.7`, since the resolution produced by the former might // work for the latter, but the inverse is unlikely to be true. let self_bound = self.env.requires_python().unwrap_or_default(); let other_bound = other.env.requires_python().unwrap_or_default(); other_bound.lower().cmp(self_bound.lower()).then_with(|| { // If there's no difference, prioritize forks with upper bounds. We'd prefer to solve // `numpy <= 2` before solving `numpy >= 1`, since the resolution produced by the former // might work for the latter, but the inverse is unlikely to be true due to maximum // version selection. (Selecting `numpy==2.0.0` would satisfy both forks, but selecting // the latest `numpy` would not.) let self_upper_bounds = self .dependencies .iter() .filter(|dep| { dep.version .bounding_range() .is_some_and(|(_, upper)| !matches!(upper, Bound::Unbounded)) }) .count(); let other_upper_bounds = other .dependencies .iter() .filter(|dep| { dep.version .bounding_range() .is_some_and(|(_, upper)| !matches!(upper, Bound::Unbounded)) }) .count(); self_upper_bounds.cmp(&other_upper_bounds) }) } } impl PartialOrd for Fork { fn partial_cmp(&self, other: &Self) -> Option { Some(self.cmp(other)) } } /// Returns an error if a conflicting extra is found in the given requirements. /// /// Specifically, if there is any conflicting extra (just one is enough) that /// is unconditionally enabled as part of a dependency specification, then this /// returns an error. /// /// The reason why we're so conservative here is because it avoids us needing /// the look at the entire dependency tree at once. /// /// For example, consider packages `root`, `a`, `b` and `c`, where `c` has /// declared conflicting extras of `x1` and `x2`. /// /// Now imagine `root` depends on `a` and `b`, `a` depends on `c[x1]` and `b` /// depends on `c[x2]`. That's a conflict, but not easily detectable unless /// you reject either `c[x1]` or `c[x2]` on the grounds that `x1` and `x2` are /// conflicting and thus cannot be enabled unconditionally. fn find_conflicting_extra(conflicting: &Conflicts, reqs: &[Requirement]) -> Option { for req in reqs { for extra in &req.extras { if conflicting.contains(&req.name, extra) { return Some(ResolveError::ConflictingExtra { requirement: Box::new(req.clone()), extra: extra.clone(), }); } } } None }