Avoid rejecting already-installed URL distributions with `--no-sources` (#16094)

## Summary

This PR removes a guard that was accidentally included in
https://github.com/astral-sh/uv/pull/15234/files#diff-6be6d80fe4821c47b70a372260f55e73b8da8182b8dcad7525d5cd3eb584532b.
I meant to remove that logic before merging.

Closes https://github.com/astral-sh/uv/issues/16068.

crates/uv-resolver/src/candidate_selector.rs

@@ -6,10 +6,8 @@ use pubgrub::Range;
 use smallvec::SmallVec;
 use tracing::{debug, trace};
 
-use uv_configuration::{IndexStrategy, SourceStrategy};
-use uv_distribution_types::{
-    CompatibleDist, IncompatibleDist, IncompatibleSource, IndexUrl, InstalledDistKind,
-};
+use uv_configuration::IndexStrategy;
+use uv_distribution_types::{CompatibleDist, IncompatibleDist, IncompatibleSource, IndexUrl};
 use uv_distribution_types::{DistributionMetadata, IncompatibleWheel, Name, PrioritizedDist};
 use uv_normalize::PackageName;
 use uv_pep440::Version;
@@ -28,7 +26,6 @@ pub(crate) struct CandidateSelector {
     resolution_strategy: ResolutionStrategy,
     prerelease_strategy: PrereleaseStrategy,
     index_strategy: IndexStrategy,
-    source_strategy: SourceStrategy,
 }
 
 impl CandidateSelector {
@@ -37,7 +34,6 @@ impl CandidateSelector {
         options: &Options,
         manifest: &Manifest,
         env: &ResolverEnvironment,
-        source_strategy: SourceStrategy,
     ) -> Self {
         Self {
             resolution_strategy: ResolutionStrategy::from_mode(
@@ -53,7 +49,6 @@ impl CandidateSelector {
                 options.dependency_mode,
             ),
             index_strategy: options.index_strategy,
-            source_strategy,
         }
     }
 
@@ -124,13 +119,7 @@ impl CandidateSelector {
         let installed = if reinstall {
             None
         } else {
-            Self::get_installed(
-                package_name,
-                range,
-                installed_packages,
-                tags,
-                self.source_strategy,
-            )
+            Self::get_installed(package_name, range, installed_packages, tags)
         };
 
         // If we're not upgrading, we should prefer the already-installed distribution.
@@ -380,7 +369,6 @@ impl CandidateSelector {
         range: &Range<Version>,
         installed_packages: &'a InstalledPackages,
         tags: Option<&'a Tags>,
-        source_strategy: SourceStrategy,
     ) -> Option<Candidate<'a>> {
         let installed_dists = installed_packages.get_packages(package_name);
         match installed_dists.as_slice() {
@@ -393,16 +381,6 @@ impl CandidateSelector {
                     return None;
                 }
 
-                // When sources are disabled, only allow registry installations to be reused
-                if matches!(source_strategy, SourceStrategy::Disabled) {
-                    if !matches!(dist.kind, InstalledDistKind::Registry(_)) {
-                        debug!(
-                            "Source strategy is disabled, rejecting non-registry installed distribution: {dist}"
-                        );
-                        return None;
-                    }
-                }
-
                 // Verify that the installed distribution is compatible with the environment.
                 if tags.is_some_and(|tags| {
                     let Ok(Some(wheel_tags)) = dist.read_tags() else {

crates/uv-resolver/src/resolver/mod.rs

@@ -20,7 +20,7 @@ use tokio::sync::oneshot;
 use tokio_stream::wrappers::ReceiverStream;
 use tracing::{Level, debug, info, instrument, trace, warn};
 
-use uv_configuration::{Constraints, Overrides, SourceStrategy};
+use uv_configuration::{Constraints, Overrides};
 use uv_distribution::{ArchiveMetadata, DistributionDatabase};
 use uv_distribution_types::{
     BuiltDist, CompatibleDist, DerivationChain, Dist, DistErrorKind, DistributionMetadata,
@@ -201,7 +201,6 @@ impl<'a, Context: BuildContext, InstalledPackages: InstalledPackagesProvider>
             build_context.git(),
             build_context.capabilities(),
             build_context.locations(),
-            build_context.sources(),
             provider,
             installed_packages,
         )
@@ -225,7 +224,6 @@ impl<Provider: ResolverProvider, InstalledPackages: InstalledPackagesProvider>
         git: &GitResolver,
         capabilities: &IndexCapabilities,
         locations: &IndexLocations,
-        source_strategy: SourceStrategy,
         provider: Provider,
         installed_packages: InstalledPackages,
     ) -> Result<Self, ResolveError> {
@@ -233,7 +231,7 @@ impl<Provider: ResolverProvider, InstalledPackages: InstalledPackagesProvider>
             index: index.clone(),
             git: git.clone(),
             capabilities: capabilities.clone(),
-            selector: CandidateSelector::for_resolution(&options, &manifest, &env, source_strategy),
+            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),

crates/uv/tests/it/pip_install.rs

@@ -12358,6 +12358,87 @@ fn reject_invalid_short_usize_zip64() {
     );
 }
 
+/// Regression test for: <https://github.com/astral-sh/uv/issues/16068>
+#[test]
+fn already_installed_url_dependency_no_sources() -> Result<()> {
+    let context = TestContext::new("3.12").with_filtered_counts();
+
+    context
+        .temp_dir
+        .child("foo")
+        .child("pyproject.toml")
+        .write_str(indoc! {r#"
+        [project]
+        name = "foo"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["iniconfig"]
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+    "#})?;
+    context
+        .temp_dir
+        .child("foo")
+        .child("src")
+        .child("foo")
+        .child("__init__.py")
+        .touch()?;
+
+    context
+        .temp_dir
+        .child("bar")
+        .child("pyproject.toml")
+        .write_str(indoc! {r#"
+        [project]
+        name = "bar"
+        version = "0.1.0"
+        requires-python = ">=3.12"
+        dependencies = ["foo"]
+
+        [build-system]
+        requires = ["hatchling"]
+        build-backend = "hatchling.build"
+    "#})?;
+    context
+        .temp_dir
+        .child("bar")
+        .child("src")
+        .child("bar")
+        .child("__init__.py")
+        .touch()?;
+
+    // Install `foo`.
+    uv_snapshot!(context.filters(), context.pip_install().arg("./foo"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved [N] packages in [TIME]
+    Prepared [N] packages in [TIME]
+    Installed [N] packages in [TIME]
+     + foo==0.1.0 (from file://[TEMP_DIR]/foo)
+     + iniconfig==2.0.0
+    ");
+
+    // Install `bar` with `--no-sources`.
+    uv_snapshot!(context.filters(), context.pip_install().arg("./bar").arg("--no-sources"), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved [N] packages in [TIME]
+    Prepared [N] packages in [TIME]
+    Installed [N] packages in [TIME]
+     + bar==0.1.0 (from file://[TEMP_DIR]/bar)
+    ");
+
+    Ok(())
+}
+
 /// Test that build dependencies respect locked versions from the resolution.
 #[test]
 fn pip_install_build_dependencies_respect_locked_versions() -> Result<()> {