Add hidden --show-version to uv check (#19892)

## Summary

Adds hidden `uv check --show-version` support, matching the existing `uv
format --show-version` convention. The flag now reports `Using ty
<version>` for both `TY` executable overrides and resolved/downloaded ty
binaries, without relying on debug logging or the separate lock-pinning
work.

This threads the hidden flag through CLI/settings/check execution and
updates focused integration coverage for both version-selection paths.

crates/uv-cli/src/lib.rs

@@ -5388,6 +5388,10 @@ pub struct CheckArgs {
     #[arg(long, value_hint = ValueHint::Other)]
     pub ty_version: Option<String>,
 
+    /// Display the version of ty that will be used for type checking.
+    #[arg(long, hide = true)]
+    pub show_version: bool,
+
     /// Avoid discovering a project or workspace.
     ///
     /// Instead of running checks in the context of the current project, run them in the context of

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

@@ -49,6 +49,7 @@ pub(crate) async fn check(
     install_mirrors: PythonInstallMirrors,
     settings: ResolverInstallerSettings,
     ty_version: Option<String>,
+    show_version: bool,
     client_builder: BaseClientBuilder<'_>,
     python_preference: PythonPreference,
     python_downloads: PythonDownloads,
@@ -387,6 +388,7 @@ pub(crate) async fn check(
         venv_path.as_deref(),
         workspace_metadata,
         exclude_newer,
+        show_version,
         &client_builder,
         cache,
         printer,

crates/uv/src/commands/project/check/ty.rs

@@ -1,3 +1,4 @@
+use std::fmt::Write;
 use std::path::{Path, PathBuf};
 use std::process::Stdio;
 use std::str::FromStr;
@@ -42,12 +43,13 @@ pub(super) async fn run(
     venv_path: Option<&Path>,
     workspace_metadata: Option<String>,
     exclude_newer: Option<jiff::Timestamp>,
+    show_version: bool,
     client_builder: &BaseClientBuilder<'_>,
     cache: &Cache,
     printer: Printer,
 ) -> Result<ExitStatus> {
     let ty_path = if let Some(ty_path) = ty_path {
-        if tracing::enabled!(tracing::Level::DEBUG) {
+        if show_version {
             let output = Command::new(&ty_path)
                 .arg("--version")
                 .output()
@@ -56,7 +58,8 @@ pub(super) async fn run(
             if !output.status.success() {
                 anyhow::bail!("Failed to query ty version");
             }
-            debug!("Using `{}`", String::from_utf8_lossy(&output.stdout).trim());
+            let version = String::from_utf8_lossy(&output.stdout);
+            writeln!(printer.stderr(), "Using {}", version.trim())?;
         }
         ty_path
     } else {
@@ -123,6 +126,10 @@ pub(super) async fn run(
             }
         };
 
+        if show_version {
+            writeln!(printer.stderr(), "Using ty {}", resolved.version)?;
+        }
+
         bin_install(
             Binary::Ty,
             &resolved,

crates/uv/src/lib.rs

@@ -2800,6 +2800,7 @@ async fn run_project(
                 args.install_mirrors,
                 args.settings,
                 args.ty_version,
+                args.show_version,
                 client_builder.subcommand(vec!["check".to_owned()]),
                 globals.python_preference,
                 globals.python_downloads,

crates/uv/src/settings.rs

@@ -2986,6 +2986,7 @@ pub(crate) struct CheckSettings {
     pub(crate) refresh: Refresh,
     pub(crate) settings: ResolverInstallerSettings,
     pub(crate) ty_version: Option<String>,
+    pub(crate) show_version: bool,
     pub(crate) no_project: bool,
     pub(crate) malware_settings: MalwareCheckSettings,
 }
@@ -3016,6 +3017,7 @@ impl CheckSettings {
             isolated,
             python,
             ty_version,
+            show_version,
             no_project,
             installer,
             build,
@@ -3082,6 +3084,7 @@ impl CheckSettings {
             refresh: Refresh::from(refresh),
             settings,
             ty_version,
+            show_version,
             no_project,
             malware_settings,
         }

crates/uv/tests/project/check.rs

@@ -65,8 +65,7 @@ fn check_uses_ty_from_environment() -> Result<()> {
             .arg("--no-project")
             .arg("--ty-version")
             .arg(">=999.0.0")
-            .arg("--verbose")
-            .env(EnvVars::RUST_LOG, "uv::commands::project::check::ty=debug")
+            .arg("--show-version")
             .env(EnvVars::TY, ty.as_os_str()),
         @"
     success: true
@@ -76,7 +75,7 @@ fn check_uses_ty_from_environment() -> Result<()> {
 
     ----- stderr -----
     warning: `uv check` is experimental and may change without warning. Pass `--preview-features check-command` to disable this warning.
-    DEBUG Using `ty 0.0.17`
+    Using ty 0.0.17
     "
     );
 
@@ -210,15 +209,17 @@ fn check_ty_version_no_match() {
 }
 
 #[test]
-fn check_ty_version_pinned_verbose() -> Result<()> {
-    let context = uv_test::test_context_with_versions!(&[]);
+fn check_ty_version_show_version() -> Result<()> {
+    let context = uv_test::test_context_with_versions!(&[]).with_filter((
+        r"(?m)^WARN Failed to fetch `ty` from .+; falling back to .+\n",
+        "",
+    ));
 
     let main_py = context.temp_dir.child("main.py");
     main_py.write_str(indoc! {r"
         x: int = 1
     "})?;
 
-    // Narrow verbose logging to the version selection this test exercises.
     uv_snapshot!(
         context.filters(),
         context
@@ -226,8 +227,7 @@ fn check_ty_version_pinned_verbose() -> Result<()> {
             .arg("--no-project")
             .arg("--ty-version")
             .arg("0.0.17")
-            .arg("--verbose")
-            .env(EnvVars::RUST_LOG, "uv::commands::project::check::ty=debug"),
+            .arg("--show-version"),
         @"
     success: true
     exit_code: 0
@@ -236,8 +236,7 @@ fn check_ty_version_pinned_verbose() -> Result<()> {
 
     ----- stderr -----
     warning: `uv check` is experimental and may change without warning. Pass `--preview-features check-command` to disable this warning.
-    DEBUG `--exclude-newer` is ignored for pinned version `0.0.17`
-    DEBUG Using `ty==0.0.17`
+    Using ty 0.0.17
     "
     );