Avoid panicking when encountering an invalid Python version during `u…

…v python list` (#7131)

Closes #7129

Not entirely sure about the best approach yet.

crates/uv-python/src/downloads.rs

@@ -529,7 +529,9 @@ impl ManagedPythonDownload {
     }
 
     pub fn python_version(&self) -> PythonVersion {
-        self.key.version()
+        self.key
+            .version()
+            .expect("Managed Python downloads should always have valid versions")
     }
 
     /// Return the [`Url`] to use when downloading the distribution. If a mirror is set via the

crates/uv-python/src/installation.rs

@@ -242,9 +242,8 @@ impl PythonInstallationKey {
         &self.implementation
     }
 
-    pub fn version(&self) -> PythonVersion {
+    pub fn version(&self) -> Result<PythonVersion, String> {
         PythonVersion::from_str(&format!("{}.{}.{}", self.major, self.minor, self.patch))
-            .expect("Python installation keys must have valid Python versions")
     }
 
     pub fn arch(&self) -> &Arch {
@@ -338,7 +337,12 @@ impl Ord for PythonInstallationKey {
     fn cmp(&self, other: &Self) -> std::cmp::Ordering {
         self.implementation
             .cmp(&other.implementation)
-            .then_with(|| self.version().cmp(&other.version()))
+            .then_with(|| {
+                self.major
+                    .cmp(&other.major)
+                    .then_with(|| self.minor.cmp(&other.minor))
+                    .then_with(|| self.patch.cmp(&other.patch))
+            })
             .then_with(|| self.os.to_string().cmp(&other.os.to_string()))
             .then_with(|| self.arch.to_string().cmp(&other.arch.to_string()))
             .then_with(|| self.libc.to_string().cmp(&other.libc.to_string()))

crates/uv-python/src/managed.rs

@@ -282,7 +282,9 @@ impl ManagedPythonInstallation {
 
     /// The [`PythonVersion`] of the toolchain.
     pub fn version(&self) -> PythonVersion {
-        self.key.version()
+        self.key
+            .version()
+            .expect("Managed Python installations should always have valid versions")
     }
 
     pub fn implementation(&self) -> &ImplementationName {
@@ -329,13 +331,17 @@ impl ManagedPythonInstallation {
         let stdlib = if matches!(self.key.os, Os(target_lexicon::OperatingSystem::Windows)) {
             self.python_dir().join("Lib")
         } else {
+            let version = self
+                .key
+                .version()
+                .expect("Managed Python installations should always have valid versions");
             let python = if matches!(
                 self.key.implementation,
                 LenientImplementationName::Known(ImplementationName::PyPy)
             ) {
-                format!("pypy{}", self.key.version().python_version())
+                format!("pypy{}", version.python_version())
             } else {
-                format!("python{}", self.key.version().python_version())
+                format!("python{}", version.python_version())
             };
             self.python_dir().join("lib").join(python)
         };

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

@@ -178,7 +178,13 @@ pub(crate) async fn install(
                 "{}",
                 format!(
                     "Installed {} {}",
-                    format!("Python {}", installed.version()).bold(),
+                    format!(
+                        "Python {}",
+                        installed.version().expect(
+                            "Managed Python installations should always have valid versions"
+                        )
+                    )
+                    .bold(),
                     format!("in {}", elapsed(start.elapsed())).dimmed()
                 )
                 .dimmed()

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

@@ -4,6 +4,7 @@ use std::fmt::Write;
 use anyhow::Result;
 use owo_colors::OwoColorize;
 use rustc_hash::FxHashSet;
+use tracing::warn;
 use uv_cache::Cache;
 use uv_fs::Simplified;
 use uv_python::downloads::PythonDownloadRequest;