Treat uninstallable packages as warnings, rather than errors (#2557)

## Summary

Closes https://github.com/astral-sh/uv/issues/2467.

crates/uv-installer/src/lib.rs

@@ -4,7 +4,7 @@ pub use editable::{is_dynamic, BuiltEditable, ResolvedEditable};
 pub use installer::{Installer, Reporter as InstallReporter};
 pub use plan::{Plan, Planner, Reinstall};
 pub use site_packages::{Diagnostic, SitePackages};
-pub use uninstall::uninstall;
+pub use uninstall::{uninstall, UninstallError};
 pub use uv_traits::NoBinary;
 
 mod compile;

crates/uv-installer/src/uninstall.rs

@@ -3,7 +3,9 @@ use anyhow::Result;
 use distribution_types::InstalledDist;
 
 /// Uninstall a package from the specified Python environment.
-pub async fn uninstall(dist: &InstalledDist) -> Result<install_wheel_rs::Uninstall> {
+pub async fn uninstall(
+    dist: &InstalledDist,
+) -> Result<install_wheel_rs::Uninstall, UninstallError> {
     let uninstall = tokio::task::spawn_blocking({
         let path = dist.path().to_owned();
         move || install_wheel_rs::uninstall_wheel(&path)
@@ -12,3 +14,11 @@ pub async fn uninstall(dist: &InstalledDist) -> Result<install_wheel_rs::Uninsta
 
     Ok(uninstall)
 }
+
+#[derive(thiserror::Error, Debug)]
+pub enum UninstallError {
+    #[error(transparent)]
+    Uninstall(#[from] install_wheel_rs::Error),
+    #[error(transparent)]
+    Join(#[from] tokio::task::JoinError),
+}

crates/uv/src/commands/pip_install.rs

@@ -35,6 +35,7 @@ use uv_resolver::{
     ResolutionGraph, ResolutionMode, Resolver,
 };
 use uv_traits::{BuildIsolation, ConfigSettings, InFlight, NoBuild, SetupPyStrategy};
+use uv_warnings::warn_user;
 
 use crate::commands::reporters::{DownloadReporter, InstallReporter, ResolverReporter};
 use crate::commands::{compile_bytecode, elapsed, ChangeEvent, ChangeEventKind, ExitStatus};
@@ -671,7 +672,8 @@ async fn install(
     // Remove any existing installations.
     if !reinstalls.is_empty() {
         for dist_info in &reinstalls {
-            let summary = uv_installer::uninstall(dist_info).await?;
+            match uv_installer::uninstall(dist_info).await {
+                Ok(summary) => {
                     debug!(
                         "Uninstalled {} ({} file{}, {} director{})",
                         dist_info.name(),
@@ -681,6 +683,17 @@ async fn install(
                         if summary.dir_count == 1 { "y" } else { "ies" },
                     );
                 }
+                Err(uv_installer::UninstallError::Uninstall(
+                    install_wheel_rs::Error::MissingRecord(_),
+                )) => {
+                    warn_user!(
+                        "Failed to uninstall package at {} due to missing RECORD file. Installation may result in an incomplete environment.",
+                        dist_info.path().simplified_display().cyan(),
+                    );
+                }
+                Err(err) => return Err(err.into()),
+            }
+        }
     }
 
     // Install the resolved distributions.
@@ -939,6 +952,9 @@ enum Error {
     #[error(transparent)]
     Resolve(#[from] uv_resolver::ResolveError),
 
+    #[error(transparent)]
+    Uninstall(#[from] uv_installer::UninstallError),
+
     #[error(transparent)]
     Client(#[from] uv_client::Error),
 

crates/uv/src/commands/pip_sync.rs

@@ -21,6 +21,7 @@ use uv_installer::{
 use uv_interpreter::{Interpreter, PythonEnvironment};
 use uv_resolver::InMemoryIndex;
 use uv_traits::{BuildIsolation, ConfigSettings, InFlight, NoBuild, SetupPyStrategy};
+use uv_warnings::warn_user;
 
 use crate::commands::reporters::{DownloadReporter, FinderReporter, InstallReporter};
 use crate::commands::{compile_bytecode, elapsed, ChangeEvent, ChangeEventKind, ExitStatus};
@@ -286,7 +287,8 @@ pub(crate) async fn pip_sync(
         let start = std::time::Instant::now();
 
         for dist_info in extraneous.iter().chain(reinstalls.iter()) {
-            let summary = uv_installer::uninstall(dist_info).await?;
+            match uv_installer::uninstall(dist_info).await {
+                Ok(summary) => {
                     debug!(
                         "Uninstalled {} ({} file{}, {} director{})",
                         dist_info.name(),
@@ -296,6 +298,17 @@ pub(crate) async fn pip_sync(
                         if summary.dir_count == 1 { "y" } else { "ies" },
                     );
                 }
+                Err(uv_installer::UninstallError::Uninstall(
+                    install_wheel_rs::Error::MissingRecord(_),
+                )) => {
+                    warn_user!(
+                        "Failed to uninstall package at {} due to missing RECORD file. Installation may result in an incomplete environment.",
+                        dist_info.path().simplified_display().cyan(),
+                    );
+                }
+                Err(err) => return Err(err.into()),
+            }
+        }
 
         let s = if extraneous.len() + reinstalls.len() == 1 {
             ""

crates/uv/tests/pip_install.rs

@@ -434,6 +434,71 @@ fn reinstall_extras() -> Result<()> {
     Ok(())
 }
 
+/// Warn, but don't fail, when uninstalling incomplete packages.
+#[test]
+#[cfg(unix)]
+fn reinstall_incomplete() -> Result<()> {
+    let context = TestContext::new("3.12");
+
+    // Install anyio.
+    let requirements_txt = context.temp_dir.child("requirements.txt");
+    requirements_txt.touch()?;
+    requirements_txt.write_str("anyio==3.7.0")?;
+
+    uv_snapshot!(command(&context)
+        .arg("-r")
+        .arg("requirements.txt"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Downloaded 3 packages in [TIME]
+    Installed 3 packages in [TIME]
+     + anyio==3.7.0
+     + idna==3.4
+     + sniffio==1.3.0
+    "###
+    );
+
+    // Manually remove the `RECORD` file.
+    fs_err::remove_file(
+        context
+            .venv
+            .join("lib/python3.12/site-packages/anyio-3.7.0.dist-info/RECORD"),
+    )?;
+
+    // Re-install anyio.
+    let requirements_txt = context.temp_dir.child("requirements.txt");
+    requirements_txt.touch()?;
+    requirements_txt.write_str("anyio==4.0.0")?;
+
+    let filters = [(r"Failed to uninstall package at .* due to missing RECORD", "Failed to uninstall package at .venv/lib/python3.12/site-packages/anyio-3.7.0.dist-info due to missing RECORD")]
+        .into_iter()
+        .chain(INSTA_FILTERS.to_vec())
+        .collect::<Vec<_>>();
+
+    uv_snapshot!(filters, command(&context)
+        .arg("-r")
+        .arg("requirements.txt"), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    Resolved 3 packages in [TIME]
+    Downloaded 1 package in [TIME]
+    warning: Failed to uninstall package at .venv/lib/python3.12/site-packages/anyio-3.7.0.dist-info due to missing RECORD file. Installation may result in an incomplete environment.
+    Installed 1 package in [TIME]
+     - anyio==3.7.0
+     + anyio==4.0.0
+    "###
+    );
+
+    Ok(())
+}
+
 /// Like `pip`, we (unfortunately) allow incompatible environments.
 #[test]
 fn allow_incompatibilities() -> Result<()> {