Allow cached environment reuse with @latest (#15827)

## Summary

I think this is leftover from a prior refactor whereby we used to avoid
reusing the cached environment if `--reinstall` was passed; but then we
stopped allowing `--reinstall` in `uv tool run` anyway, and this got
changed to `--refresh`. It seems wrong to skip cache reuse with
`--refresh`, though.

Closes #15824.

Author: charliermarsh

crates/uv/src/commands/project/environment.rs

@@ -174,11 +174,9 @@ impl CachedEnvironment {
         // Search in the content-addressed cache.
         let cache_entry = cache.entry(CacheBucket::Environments, interpreter_hash, resolution_hash);
 
-        if cache.refresh().is_none() {
-            if let Ok(root) = cache.resolve_link(cache_entry.path()) {
-                if let Ok(environment) = PythonEnvironment::from_root(root, cache) {
-                    return Ok(Self(environment));
-                }
+        if let Ok(root) = cache.resolve_link(cache_entry.path()) {
+            if let Ok(environment) = PythonEnvironment::from_root(root, cache) {
+                return Ok(Self(environment));
             }
         }
 

crates/uv/src/settings.rs

@@ -536,11 +536,11 @@ impl ToolRunSettings {
         if installer.reinstall || !installer.reinstall_package.is_empty() {
             if with.is_empty() && with_requirements.is_empty() {
                 warn_user_once!(
-                    "Tools cannot be reinstalled via `{invocation_source}`; use `uv tool upgrade --all --reinstall` to reinstall all installed tools, or `{invocation_source} package@latest` to run the latest version of a tool."
+                    "Tools cannot be reinstalled via `{invocation_source}`; use `uv tool upgrade --all --reinstall` to reinstall all installed tools, `{invocation_source} package@latest` to run the latest version of a tool, or `uv cache prune` to clear any cached tool environments."
                 );
             } else {
                 warn_user_once!(
-                    "Tools cannot be reinstalled via `{invocation_source}`; use `uv tool upgrade --all --reinstall` to reinstall all installed tools, `{invocation_source} package@latest` to run the latest version of a tool, or `{invocation_source} --refresh package` to reinstall any `--with` dependencies."
+                    "Tools cannot be reinstalled via `{invocation_source}`; use `uv tool upgrade --all --reinstall` to reinstall all installed tools, `{invocation_source} package@latest` to run the latest version of a tool, `{invocation_source} --refresh package` to reinstall any `--with` dependencies, or `uv cache prune` to clear any cached tool environments."
                 );
             }
         }

crates/uv/tests/it/tool_run.rs

@@ -734,15 +734,15 @@ fn tool_run_cache() {
     Resolved [N] packages in [TIME]
     "###);
 
-    // Verify that `--refresh` recreates everything.
+    // Verify that `--refresh` allows cache reuse.
     uv_snapshot!(context.filters(), context.tool_run()
         .arg("-p")
         .arg("3.12")
         .arg("--refresh")
         .arg("black")
         .arg("--version")
         .env(EnvVars::UV_TOOL_DIR, tool_dir.as_os_str())
-        .env(EnvVars::XDG_BIN_HOME, bin_dir.as_os_str()), @r###"
+        .env(EnvVars::XDG_BIN_HOME, bin_dir.as_os_str()), @r"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -751,17 +751,9 @@ fn tool_run_cache() {
 
     ----- stderr -----
     Resolved [N] packages in [TIME]
-    Prepared [N] packages in [TIME]
-    Installed [N] packages in [TIME]
-     + black==24.3.0
-     + click==8.1.7
-     + mypy-extensions==1.0.0
-     + packaging==24.0
-     + pathspec==0.12.1
-     + platformdirs==4.2.0
-    "###);
+    ");
 
-    // Verify that `--refresh-package` recreates everything. We may want to change this.
+    // Verify that `--refresh-package` allows cache reuse.
     uv_snapshot!(context.filters(), context.tool_run()
         .arg("-p")
         .arg("3.12")
@@ -770,7 +762,7 @@ fn tool_run_cache() {
         .arg("black")
         .arg("--version")
         .env(EnvVars::UV_TOOL_DIR, tool_dir.as_os_str())
-        .env(EnvVars::XDG_BIN_HOME, bin_dir.as_os_str()), @r###"
+        .env(EnvVars::XDG_BIN_HOME, bin_dir.as_os_str()), @r"
     success: true
     exit_code: 0
     ----- stdout -----
@@ -779,15 +771,7 @@ fn tool_run_cache() {
 
     ----- stderr -----
     Resolved [N] packages in [TIME]
-    Prepared [N] packages in [TIME]
-    Installed [N] packages in [TIME]
-     + black==24.3.0
-     + click==8.1.7
-     + mypy-extensions==1.0.0
-     + packaging==24.0
-     + pathspec==0.12.1
-     + platformdirs==4.2.0
-    "###);
+    ");
 
     // Verify that varying the interpreter leads to a fresh environment.
     uv_snapshot!(context.filters(), context.tool_run()