Add uv tool install (#4492)

This is the minimal "working" implementation. In summary, we:

- Resolve the requested requirements
- Create an environment at `$UV_STATE_DIR/tools/$name`
- Inspect the `dist-info` for the main requirement to determine its
entry points scripts
- Link the entry points from a user-executable directory
(`$XDG_BIN_HOME`) to the environment bin
- Create an entry at `$UV_STATE_DIR/tools/tools.toml` tracking the
user's request

The idea with `tools.toml` is that it allows us to perform upgrades and
syncs, retaining the original user request (similar to declarations in a
`pyproject.toml`). I imagine using a similar schema in the
`pyproject.toml` in the future if/when we add project-levle tools. I'm
also considering exposing `tools.toml` in the standard uv configuration
directory instead of the state directory, but it seems nice to tuck it
away for now while we iterate on it. Installing a tool won't perform a
sync of other tool environments, we'll probably have an explicit `uv
tool sync` command for that?

I've split out todos into follow-up pull requests:

- #4509 (failing on Windows)
- #4501 
- #4504 

Closes #4485

crates/install-wheel-rs/src/lib.rs

@@ -11,9 +11,11 @@ use zip::result::ZipError;
 use pep440_rs::Version;
 use platform_tags::{Arch, Os};
 use pypi_types::Scheme;
+pub use script::{scripts_from_ini, Script};
 pub use uninstall::{uninstall_egg, uninstall_legacy_editable, uninstall_wheel, Uninstall};
 use uv_fs::Simplified;
 use uv_normalize::PackageName;
+pub use wheel::{parse_wheel_file, LibKind};
 
 pub mod linker;
 pub mod metadata;

crates/install-wheel-rs/src/linker.rs

@@ -1,7 +1,7 @@
 //! Like `wheel.rs`, but for installing wheels that have already been unzipped, rather than
 //! reading from a zip file.
 
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::str::FromStr;
 use std::time::SystemTime;
 
@@ -143,6 +143,24 @@ pub fn install_wheel(
     Ok(())
 }
 
+/// Determine the absolute path to an entrypoint script.
+pub fn entrypoint_path(entrypoint: &Script, layout: &Layout) -> PathBuf {
+    if cfg!(windows) {
+        // On windows we actually build an .exe wrapper
+        let script_name = entrypoint
+            .name
+            // FIXME: What are the in-reality rules here for names?
+            .strip_suffix(".py")
+            .unwrap_or(&entrypoint.name)
+            .to_string()
+            + ".exe";
+
+        layout.scheme.scripts.join(script_name)
+    } else {
+        layout.scheme.scripts.join(&entrypoint.name)
+    }
+}
+
 /// Find the `dist-info` directory in an unzipped wheel.
 ///
 /// See: <https://github.com/PyO3/python-pkginfo-rs>

crates/install-wheel-rs/src/script.rs

@@ -9,10 +9,10 @@ use crate::{wheel, Error};
 /// A script defining the name of the runnable entrypoint and the module and function that should be
 /// run.
 #[derive(Clone, Debug, Eq, PartialEq, Serialize)]
-pub(crate) struct Script {
-    pub(crate) name: String,
-    pub(crate) module: String,
-    pub(crate) function: String,
+pub struct Script {
+    pub name: String,
+    pub module: String,
+    pub function: String,
 }
 
 impl Script {
@@ -64,7 +64,7 @@ impl Script {
     }
 }
 
-pub(crate) fn scripts_from_ini(
+pub fn scripts_from_ini(
     extras: Option<&[String]>,
     python_minor: u8,
     ini: String,

crates/install-wheel-rs/src/wheel.rs

@@ -17,6 +17,7 @@ use zip::ZipWriter;
 use pypi_types::DirectUrl;
 use uv_fs::{relative_to, Simplified};
 
+use crate::linker::entrypoint_path;
 use crate::record::RecordEntry;
 use crate::script::Script;
 use crate::{Error, Layout};
@@ -255,20 +256,7 @@ pub(crate) fn write_script_entrypoints(
     is_gui: bool,
 ) -> Result<(), Error> {
     for entrypoint in entrypoints {
-        let entrypoint_absolute = if cfg!(windows) {
-            // On windows we actually build an .exe wrapper
-            let script_name = entrypoint
-                .name
-                // FIXME: What are the in-reality rules here for names?
-                .strip_suffix(".py")
-                .unwrap_or(&entrypoint.name)
-                .to_string()
-                + ".exe";
-
-            layout.scheme.scripts.join(script_name)
-        } else {
-            layout.scheme.scripts.join(&entrypoint.name)
-        };
+        let entrypoint_absolute = entrypoint_path(entrypoint, layout);
 
         let entrypoint_relative = pathdiff::diff_paths(&entrypoint_absolute, site_packages)
             .ok_or_else(|| {
@@ -320,7 +308,7 @@ pub(crate) fn write_script_entrypoints(
 
 /// Whether the wheel should be installed into the `purelib` or `platlib` directory.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub(crate) enum LibKind {
+pub enum LibKind {
     /// Install into the `purelib` directory.
     Pure,
     /// Install into the `platlib` directory.
@@ -331,7 +319,7 @@ pub(crate) enum LibKind {
 ///
 /// > {distribution}-{version}.dist-info/WHEEL is metadata about the archive itself in the same
 /// > basic key: value format:
-pub(crate) fn parse_wheel_file(wheel_text: &str) -> Result<LibKind, Error> {
+pub fn parse_wheel_file(wheel_text: &str) -> Result<LibKind, Error> {
     // {distribution}-{version}.dist-info/WHEEL is metadata about the archive itself in the same basic key: value format:
     let data = parse_key_value_file(&mut wheel_text.as_bytes(), "WHEEL")?;