Support legacy tool receipts with PEP 508 requirements (#5679)

## Summary

In #5494, I made breaking changes to the tool receipt format. This would
break existing tools for all users. This PR makes the change
backwards-compatible by supporting deserialization for the deprecated
format.

Closes https://github.com/astral-sh/uv/issues/5680.

## Test Plan

Beyond the automated tests, you can run `cargo run tool list` on your
existing machine.

Before:

```
warning: `uv tool list` is experimental and may change without warning
warning: Ignoring malformed tool `black` (run `uv tool uninstall black` to remove)
warning: Ignoring malformed tool `poetry` (run `uv tool uninstall poetry` to remove)
warning: Ignoring malformed tool `ruff` (run `uv tool uninstall ruff` to remove)
```

After:

```
warning: `uv tool list` is experimental and may change without warning
black v0.1.0
- black
poetry v1.8.3
- poetry
ruff v0.0.60
- ruff
```

crates/uv-tool/src/tool.rs

@@ -6,13 +6,13 @@ use toml_edit::Array;
 use toml_edit::Table;
 use toml_edit::Value;
 
-use pypi_types::Requirement;
+use pypi_types::{Requirement, VerbatimParsedUrl};
 use uv_fs::PortablePath;
 
 /// A tool entry.
 #[allow(dead_code)]
 #[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
-#[serde(rename_all = "kebab-case")]
+#[serde(try_from = "ToolWire", into = "ToolWire")]
 pub struct Tool {
     /// The requirements requested by the user during installation.
     requirements: Vec<Requirement>,
@@ -22,6 +22,56 @@ pub struct Tool {
     entrypoints: Vec<ToolEntrypoint>,
 }
 
+#[derive(Clone, Debug, Deserialize)]
+pub struct ToolWire {
+    pub requirements: Vec<RequirementWire>,
+    pub python: Option<String>,
+    pub entrypoints: Vec<ToolEntrypoint>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+#[serde(untagged)]
+pub enum RequirementWire {
+    /// A [`Requirement`] following our uv-specific schema.
+    Requirement(Requirement),
+    /// A PEP 508-compatible requirement. We no longer write these, but there might be receipts out
+    /// there that still use them.
+    Deprecated(pep508_rs::Requirement<VerbatimParsedUrl>),
+}
+
+impl From<Tool> for ToolWire {
+    fn from(tool: Tool) -> Self {
+        Self {
+            requirements: tool
+                .requirements
+                .into_iter()
+                .map(RequirementWire::Requirement)
+                .collect(),
+            python: tool.python,
+            entrypoints: tool.entrypoints,
+        }
+    }
+}
+
+impl TryFrom<ToolWire> for Tool {
+    type Error = serde::de::value::Error;
+
+    fn try_from(tool: ToolWire) -> Result<Self, Self::Error> {
+        Ok(Self {
+            requirements: tool
+                .requirements
+                .into_iter()
+                .map(|req| match req {
+                    RequirementWire::Requirement(requirements) => requirements,
+                    RequirementWire::Deprecated(requirement) => Requirement::from(requirement),
+                })
+                .collect(),
+            python: tool.python,
+            entrypoints: tool.entrypoints,
+        })
+    }
+}
+
 #[derive(Debug, Clone, Eq, PartialEq, Ord, PartialOrd, Deserialize)]
 #[serde(rename_all = "kebab-case")]
 pub struct ToolEntrypoint {

crates/uv/tests/tool_list.rs

@@ -3,9 +3,9 @@
 use anyhow::Result;
 use assert_cmd::assert::OutputAssertExt;
 use assert_fs::fixture::PathChild;
-use fs_err as fs;
-
 use common::{uv_snapshot, TestContext};
+use fs_err as fs;
+use insta::assert_snapshot;
 
 mod common;
 
@@ -170,3 +170,89 @@ fn tool_list_bad_environment() -> Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn tool_list_deprecated() -> Result<()> {
+    let context = TestContext::new("3.12").with_filtered_exe_suffix();
+    let tool_dir = context.temp_dir.child("tools");
+    let bin_dir = context.temp_dir.child("bin");
+
+    // Install `black`
+    context
+        .tool_install()
+        .arg("black==24.2.0")
+        .env("UV_TOOL_DIR", tool_dir.as_os_str())
+        .env("XDG_BIN_HOME", bin_dir.as_os_str())
+        .assert()
+        .success();
+
+    // Ensure that we have a modern tool receipt.
+    insta::with_settings!({
+        filters => context.filters(),
+    }, {
+        assert_snapshot!(fs_err::read_to_string(tool_dir.join("black").join("uv-receipt.toml")).unwrap(), @r###"
+        [tool]
+        requirements = [{ name = "black", specifier = "==24.2.0" }]
+        entrypoints = [
+            { name = "black", install-path = "[TEMP_DIR]/bin/black" },
+            { name = "blackd", install-path = "[TEMP_DIR]/bin/blackd" },
+        ]
+        "###);
+    });
+
+    // Replace with a legacy receipt.
+    fs::write(
+        tool_dir.join("black").join("uv-receipt.toml"),
+        r#"
+        [tool]
+        requirements = ["black==24.2.0"]
+        entrypoints = [
+            { name = "black", install-path = "[TEMP_DIR]/bin/black" },
+            { name = "blackd", install-path = "[TEMP_DIR]/bin/blackd" },
+        ]
+        "#,
+    )?;
+
+    // Ensure that we can still list the tool.
+    uv_snapshot!(context.filters(), context.tool_list()
+    .env("UV_TOOL_DIR", tool_dir.as_os_str())
+    .env("XDG_BIN_HOME", bin_dir.as_os_str()), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    black v24.2.0
+    - black
+    - blackd
+
+    ----- stderr -----
+    warning: `uv tool list` is experimental and may change without warning
+    "###);
+
+    // Replace with an invalid receipt.
+    fs::write(
+        tool_dir.join("black").join("uv-receipt.toml"),
+        r#"
+        [tool]
+        requirements = ["black<>24.2.0"]
+        entrypoints = [
+            { name = "black", install-path = "[TEMP_DIR]/bin/black" },
+            { name = "blackd", install-path = "[TEMP_DIR]/bin/blackd" },
+        ]
+        "#,
+    )?;
+
+    // Ensure that listing fails.
+    uv_snapshot!(context.filters(), context.tool_list()
+    .env("UV_TOOL_DIR", tool_dir.as_os_str())
+    .env("XDG_BIN_HOME", bin_dir.as_os_str()), @r###"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+
+    ----- stderr -----
+    warning: `uv tool list` is experimental and may change without warning
+    warning: Ignoring malformed tool `black` (run `uv tool uninstall black` to remove)
+    "###);
+
+    Ok(())
+}