Account for python_downloads_json_url on Pre-release Python version warnings

crates/uv-cli/src/lib.rs

@@ -6032,6 +6032,12 @@ pub struct PythonFindArgs {
     /// Show the Python version that would be used instead of the path to the interpreter.
     #[arg(long)]
     pub show_version: bool,
+
+    /// URL pointing to JSON of custom Python installations.
+    ///
+    /// Note that currently, only local paths are supported.
+    #[arg(long)]
+    pub python_downloads_json_url: Option<String>,
 }
 
 #[derive(Args)]

crates/uv-python/src/installation.rs

@@ -59,12 +59,13 @@ impl PythonInstallation {
         request: &PythonRequest,
         environments: EnvironmentPreference,
         preference: PythonPreference,
+        python_downloads_json_url: Option<&str>,
         cache: &Cache,
         preview: Preview,
     ) -> Result<Self, Error> {
         let installation =
             find_python_installation(request, environments, preference, cache, preview)??;
-        installation.warn_if_outdated_prerelease(request, None);
+        installation.warn_if_outdated_prerelease(request, python_downloads_json_url);
         Ok(installation)
     }
 
@@ -74,12 +75,13 @@ impl PythonInstallation {
         request: &PythonRequest,
         environments: EnvironmentPreference,
         preference: PythonPreference,
+        python_downloads_json_url: Option<&str>,
         cache: &Cache,
         preview: Preview,
     ) -> Result<Self, Error> {
         let installation =
             find_best_python_installation(request, environments, preference, cache, preview)??;
-        installation.warn_if_outdated_prerelease(request, None);
+        installation.warn_if_outdated_prerelease(request, python_downloads_json_url);
         Ok(installation)
     }
 
@@ -102,7 +104,14 @@ impl PythonInstallation {
         let request = request.unwrap_or(&PythonRequest::Default);
 
         // Search for the installation
-        let err = match Self::find(request, environments, preference, cache, preview) {
+        let err = match Self::find(
+            request,
+            environments,
+            preference,
+            python_downloads_json_url,
+            cache,
+            preview,
+        ) {
             Ok(installation) => return Ok(installation),
             Err(err) => err,
         };

crates/uv/src/commands/pip/compile.rs

@@ -44,6 +44,7 @@ use uv_resolver::{
     InMemoryIndex, OptionsBuilder, PrereleaseMode, PylockToml, PythonRequirement, ResolutionMode,
     ResolverEnvironment,
 };
+use uv_settings::PythonInstallMirrors;
 use uv_static::EnvVars;
 use uv_torch::{TorchMode, TorchSource, TorchStrategy};
 use uv_types::{EmptyInstalledPackages, HashStrategy};
@@ -102,6 +103,7 @@ pub(crate) async fn pip_compile(
     extra_build_dependencies: &ExtraBuildDependencies,
     extra_build_variables: &ExtraBuildVariables,
     build_options: BuildOptions,
+    install_mirrors: PythonInstallMirrors,
     mut python_version: Option<PythonVersion>,
     python_platform: Option<TargetTriple>,
     universal: bool,
@@ -296,6 +298,7 @@ pub(crate) async fn pip_compile(
             &request,
             environment_preference,
             python_preference,
+            install_mirrors.python_downloads_json_url.as_deref(),
             &cache,
             preview,
         )
@@ -312,6 +315,7 @@ pub(crate) async fn pip_compile(
             &request,
             environment_preference,
             python_preference,
+            install_mirrors.python_downloads_json_url.as_deref(),
             &cache,
             preview,
         )

crates/uv/src/commands/python/find.rs

@@ -31,6 +31,7 @@ pub(crate) async fn find(
     no_config: bool,
     system: bool,
     python_preference: PythonPreference,
+    python_downloads_json_url: Option<&str>,
     cache: &Cache,
     printer: Printer,
     preview: Preview,
@@ -78,6 +79,7 @@ pub(crate) async fn find(
         &python_request.unwrap_or_default(),
         environment_preference,
         python_preference,
+        python_downloads_json_url,
         cache,
         preview,
     )?;

crates/uv/src/commands/python/pin.rs

@@ -100,6 +100,7 @@ pub(crate) async fn pin(
                         pin,
                         virtual_project,
                         python_preference,
+                        install_mirrors.python_downloads_json_url.as_deref(),
                         cache,
                         preview,
                     );
@@ -264,6 +265,7 @@ fn warn_if_existing_pin_incompatible_with_project(
     pin: &PythonRequest,
     virtual_project: &VirtualProject,
     python_preference: PythonPreference,
+    python_downloads_json_url: Option<&str>,
     cache: &Cache,
     preview: Preview,
 ) {
@@ -289,6 +291,7 @@ fn warn_if_existing_pin_incompatible_with_project(
         pin,
         EnvironmentPreference::OnlySystem,
         python_preference,
+        python_downloads_json_url,
         cache,
         preview,
     ) {

crates/uv/src/lib.rs

@@ -631,6 +631,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                 &args.settings.extra_build_dependencies,
                 &args.settings.extra_build_variables,
                 args.settings.build_options,
+                args.settings.install_mirrors,
                 args.settings.python_version,
                 args.settings.python_platform,
                 args.settings.universal,
@@ -1614,7 +1615,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
             command: PythonCommand::Find(args),
         }) => {
             // Resolve the settings from the command-line arguments and workspace configuration.
-            let args = settings::PythonFindSettings::resolve(args, filesystem);
+            let args = settings::PythonFindSettings::resolve(args, filesystem, environment);
 
             // Initialize the cache.
             let cache = cache.init()?;
@@ -1641,6 +1642,7 @@ async fn run(mut cli: Cli) -> Result<ExitStatus> {
                     cli.top_level.no_config,
                     args.system,
                     globals.python_preference,
+                    args.python_downloads_json_url.as_deref(),
                     &cache,
                     printer,
                     globals.preview,

crates/uv/src/settings.rs

@@ -1235,26 +1235,50 @@ pub(crate) struct PythonFindSettings {
     pub(crate) show_version: bool,
     pub(crate) no_project: bool,
     pub(crate) system: bool,
+    pub(crate) python_downloads_json_url: Option<String>,
 }
 
 impl PythonFindSettings {
     /// Resolve the [`PythonFindSettings`] from the CLI and workspace configuration.
     #[allow(clippy::needless_pass_by_value)]
-    pub(crate) fn resolve(args: PythonFindArgs, _filesystem: Option<FilesystemOptions>) -> Self {
+    pub(crate) fn resolve(
+        args: PythonFindArgs,
+        filesystem: Option<FilesystemOptions>,
+        environment: EnvironmentOptions,
+    ) -> Self {
         let PythonFindArgs {
             request,
             show_version,
             no_project,
             system,
             no_system,
             script: _,
+            python_downloads_json_url,
         } = args;
 
+        let filesystem_install_mirrors = filesystem
+            .map(|fs| fs.install_mirrors.clone())
+            .unwrap_or_default();
+
+        let install_mirrors = PythonInstallMirrors {
+            python_downloads_json_url,
+            ..Default::default()
+        }
+        .combine(environment.install_mirrors)
+        .combine(filesystem_install_mirrors);
+
+        let PythonInstallMirrors {
+            python_install_mirror: _,
+            pypy_install_mirror: _,
+            python_downloads_json_url,
+        } = install_mirrors;
+
         Self {
             request,
             show_version,
             no_project,
             system: flag(system, no_system, "system").unwrap_or_default(),
+            python_downloads_json_url,
         }
     }
 }

crates/uv/tests/it/common/mod.rs

@@ -631,7 +631,7 @@ impl TestContext {
             .iter()
             .map(|version| PythonVersion::from_str(version).unwrap())
             .zip(
-                python_installations_for_versions(&temp_dir, python_versions)
+                python_installations_for_versions(&temp_dir, python_versions, None)
                     .expect("Failed to find test Python versions"),
             )
             .collect();
@@ -1689,7 +1689,7 @@ pub fn python_path_with_versions(
     python_versions: &[&str],
 ) -> anyhow::Result<OsString> {
     Ok(env::join_paths(
-        python_installations_for_versions(temp_dir, python_versions)?
+        python_installations_for_versions(temp_dir, python_versions, None)?
             .into_iter()
             .map(|path| path.parent().unwrap().to_path_buf()),
     )?)
@@ -1701,6 +1701,7 @@ pub fn python_path_with_versions(
 pub fn python_installations_for_versions(
     temp_dir: &ChildPath,
     python_versions: &[&str],
+    python_downloads_json_url: Option<&str>,
 ) -> anyhow::Result<Vec<PathBuf>> {
     let cache = Cache::from_path(temp_dir.child("cache").to_path_buf()).init()?;
     let selected_pythons = python_versions
@@ -1710,6 +1711,7 @@ pub fn python_installations_for_versions(
                 &PythonRequest::parse(python_version),
                 EnvironmentPreference::OnlySystem,
                 PythonPreference::Managed,
+                python_downloads_json_url,
                 &cache,
                 Preview::default(),
             ) {

docs/reference/cli.md

@@ -3686,7 +3686,9 @@ uv python find [OPTIONS] [REQUEST]
 <p>Other command-line arguments (such as relative paths) will be resolved relative to the current working directory.</p>
 <p>See <code>--directory</code> to change the working directory entirely.</p>
 <p>This setting has no effect when used in the <code>uv pip</code> interface.</p>
-<p>May also be set with the <code>UV_PROJECT</code> environment variable.</p></dd><dt id="uv-python-find--quiet"><a href="#uv-python-find--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
+<p>May also be set with the <code>UV_PROJECT</code> environment variable.</p></dd><dt id="uv-python-find--python-downloads-json-url"><a href="#uv-python-find--python-downloads-json-url"><code>--python-downloads-json-url</code></a> <i>python-downloads-json-url</i></dt><dd><p>URL pointing to JSON of custom Python installations.</p>
+<p>Note that currently, only local paths are supported.</p>
+</dd><dt id="uv-python-find--quiet"><a href="#uv-python-find--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
 <p>Repeating this option, e.g., <code>-qq</code>, will enable a silent mode in which uv will write no output to stdout.</p>
 </dd><dt id="uv-python-find--script"><a href="#uv-python-find--script"><code>--script</code></a> <i>script</i></dt><dd><p>Find the environment for a Python script, rather than the current project</p>
 </dd><dt id="uv-python-find--show-version"><a href="#uv-python-find--show-version"><code>--show-version</code></a></dt><dd><p>Show the Python version that would be used instead of the path to the interpreter</p>