fix(tools): install rust-analyzer without rustup (#490)

* fix(tools): install rust-analyzer without rustup * fix(tools): reinstall a managed rust-analyzer with the installer that made it Once rustup appeared, Reinstall ran rustup while the Open VSX copy stayed in use.
2026-11-06 08:07:49 +00:00 · 2026-10-31 10:14:55 +08:00
parent 4a620122e8
commit 4f1feebbd0
4 changed files with 243 additions and 29 deletions
@@ -138,7 +138,7 @@ fn bin_dirs_in(root: &Path, platform: Platform) -> Vec<PathBuf> {
 }

 fn managed_bin_dir(root: &Path, spec: &ToolSpec, platform: Platform) -> Option<PathBuf> {
-    match spec.method {
+    match spec.fallback.unwrap_or(spec.method) {
        Method::Npm { .. } => Some(root.join("node_modules").join(".bin")),
        Method::Go { .. } | Method::Gem { .. } | Method::DotnetTool { .. } | Method::Release { .. } => {
            Some(root.join(spec.name).join("bin"))
@@ -520,16 +520,26 @@ impl Tools {
        parse_version(&out)
    }

+    /// The installer that owns this tool: a managed copy is refreshed and removed by the
+    /// fallback that made it, even if the primary installer has appeared since.
+    fn install_method(&self, spec: &ToolSpec) -> Method {
+        let Some(fallback) = spec.fallback else { return spec.method };
+        let managed = managed_bin_dir(&self.root, spec, self.platform)
+            .and_then(|dir| self.exe_in(&dir, spec.commands[0]))
+            .is_some();
+        if managed || self.method_missing(spec.method).is_some() { fallback } else { spec.method }
+    }
+
    /// Requirement check for installing `spec` right now.
    fn unavailable_reason(&self, spec: &ToolSpec) -> Option<String> {
-        self.installer_missing(spec)
+        self.method_missing(self.install_method(spec))
            .or_else(|| spec.needs.iter().find(|(cmd, _)| self.which(cmd).is_none()).map(|(_, why)| why.to_string()))
    }

    /// What the install method itself lacks (npm, a build for this platform, …).
-    fn installer_missing(&self, spec: &ToolSpec) -> Option<String> {
+    fn method_missing(&self, method: Method) -> Option<String> {
        let need = |ok: bool, msg: &str| (!ok).then(|| msg.to_string());
-        match spec.method {
+        match method {
            Method::Rustup { .. } => need(self.which("rustup").is_some(), "rustup is required (https://rustup.rs)"),
            Method::Npm { .. } => need(
                self.which_any(&["npm", "pnpm"]).is_some(),
@@ -602,7 +612,7 @@ impl Tools {
            status,
            path: path.map(Into::into),
            version,
-            install_method: Some(spec.method.label().to_string()),
+            install_method: Some(self.install_method(spec).label().to_string()),
            can_install: unavailable_reason.is_none(),
            unavailable_reason,
            can_uninstall,
@@ -643,7 +653,16 @@ impl Tools {

    fn detect(&self, spec: &ToolSpec) -> (ToolStatus, Option<PathBuf>, Option<String>) {
        let main = spec.commands[0];
-        match spec.method {
+        let managed = managed_bin_dir(&self.root, spec, self.platform).and_then(|d| self.exe_in(&d, main));
+        if let Some(path) = managed {
+            let version = match spec.method {
+                Method::Npm { packages } => self.npm_package_version(npm_name(packages[0])),
+                _ => self.manifest(spec.name).and_then(|m| m.version),
+            }
+            .or_else(|| self.query_version(spec, &path));
+            return (ToolStatus::Installed, Some(path), version);
+        }
+        match self.install_method(spec) {
            Method::Rustup { .. } => {
                let Some(path) = self.which(main) else { return (ToolStatus::Missing, None, None) };
                // The rustup proxy exists even without the component; it only answers when installed.
@@ -678,24 +697,13 @@ impl Tools {
                    _ => (ToolStatus::Missing, None, None),
                }
            }
-            _ => {
-                let managed = managed_bin_dir(&self.root, spec, self.platform).and_then(|d| self.exe_in(&d, main));
-                if let Some(path) = managed {
-                    let version = match spec.method {
-                        Method::Npm { packages } => self.npm_package_version(npm_name(packages[0])),
-                        _ => self.manifest(spec.name).and_then(|m| m.version),
-                    }
-                    .or_else(|| self.query_version(spec, &path));
-                    return (ToolStatus::Installed, Some(path), version);
+            _ => match self.which(main) {
+                Some(path) => {
+                    let version = self.query_version(spec, &path);
+                    (ToolStatus::OnPath, Some(path), version)
                }
-                match self.which(main) {
-                    Some(path) => {
-                        let version = self.query_version(spec, &path);
-                        (ToolStatus::OnPath, Some(path), version)
-                    }
-                    None => (ToolStatus::Missing, None, None),
-                }
-            }
+                None => (ToolStatus::Missing, None, None),
+            },
        }
    }

@@ -769,8 +777,9 @@ impl Tools {
        let emit = &fan as Emit;
        let result = (|| {
            std::fs::create_dir_all(&self.root)?;
-            emit(InstallEvent::Line { text: format!("Installing {} via {}…", spec.display, spec.method.label()) });
-            match spec.method {
+            let method = self.install_method(spec);
+            emit(InstallEvent::Line { text: format!("Installing {} via {}…", spec.display, method.label()) });
+            match method {
                Method::Rustup { component } => {
                    let mut c = self.command(self.which("rustup").expect("checked"));
                    c.args(["component", "add", component]);
@@ -1072,6 +1081,10 @@ impl Tools {
            }
            ReleaseSource::OpenVsx { namespace, extension } => {
                let json = http.get_text(&sources::openvsx_latest_url(namespace, extension), cancel)?;
+                let json = match sources::openvsx_platform_url(&json, assets, self.platform)? {
+                    Some(url) => http.get_text(&url, cancel)?,
+                    None => json,
+                };
                sources::openvsx_pick(&json, assets, self.platform)
            }
            ReleaseSource::MavenCentral { group, artifact } => {
@@ -1172,7 +1185,7 @@ impl Tools {
        let _guard = InstallGuard::acquire(&format!("uninstall-{name}"))?;
        let cancel = CancellationToken::new();
        let quiet = |_: InstallEvent| {};
-        match spec.method {
+        match self.install_method(spec) {
            Method::Rustup { component } => {
                let rustup = self.which("rustup").ok_or_else(|| IdeError::unavailable("rustup not found"))?;
                let mut c = self.command(rustup);
@@ -82,6 +82,8 @@ pub struct ToolSpec {
    /// is a plugin bundle loaded by another tool (copied to `bin/` under this name).
    pub commands: &'static [&'static str],
    pub method: Method,
+    /// Used when the primary installer is unavailable.
+    pub fallback: Option<Method>,
    /// Version query: a command (looked up next to the main binary first) and its args.
    pub version: Option<(&'static str, &'static [&'static str])>,
    pub homepage: &'static str,
@@ -123,6 +125,18 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["rust-analyzer"],
        method: Method::Rustup { component: "rust-analyzer" },
+        fallback: Some(Method::Release {
+            source: ReleaseSource::OpenVsx { namespace: "rust-lang", extension: "rust-analyzer" },
+            assets: &[
+                rule(Mac, Arm64, "rust-lang.rust-analyzer-*@darwin-arm64.vsix"),
+                rule(Mac, X64, "rust-lang.rust-analyzer-*@darwin-x64.vsix"),
+                rule(Linux, Arm64, "rust-lang.rust-analyzer-*@linux-arm64.vsix"),
+                rule(Linux, X64, "rust-lang.rust-analyzer-*@linux-x64.vsix"),
+                rule(Windows, Arm64, "rust-lang.rust-analyzer-*@win32-arm64.vsix"),
+                rule(Windows, X64, "rust-lang.rust-analyzer-*@win32-x64.vsix"),
+            ],
+            locate: &["rust-analyzer"],
+        }),
        version: ver("rust-analyzer"),
        homepage: "https://rust-analyzer.github.io",
        needs: &[],
@@ -133,6 +147,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["vtsls"],
        method: Method::Npm { packages: &["@vtsls/language-server"] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/yioneko/vtsls",
        needs: &[],
@@ -143,6 +158,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["typescript-language-server"],
        method: Method::Npm { packages: &["typescript-language-server", TYPESCRIPT] },
+        fallback: None,
        version: ver("typescript-language-server"),
        homepage: "https://github.com/typescript-language-server/typescript-language-server",
        needs: &[],
@@ -153,6 +169,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["pyright-langserver", "pyright"],
        method: Method::Npm { packages: &["pyright"] },
+        fallback: None,
        version: ver("pyright"),
        homepage: "https://github.com/microsoft/pyright",
        needs: &[],
@@ -163,6 +180,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["basedpyright-langserver", "basedpyright"],
        method: Method::PipVenv { package: "basedpyright" },
+        fallback: None,
        version: ver("basedpyright"),
        homepage: "https://docs.basedpyright.com",
        needs: &[],
@@ -173,6 +191,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["ty"],
        method: Method::PipVenv { package: "ty" },
+        fallback: None,
        version: ver("ty"),
        homepage: "https://docs.astral.sh/ty/",
        needs: &[],
@@ -183,6 +202,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["bash-language-server"],
        method: Method::Npm { packages: &["bash-language-server"] },
+        fallback: None,
        version: ver("bash-language-server"),
        homepage: "https://github.com/bash-lsp/bash-language-server",
        needs: &[],
@@ -193,6 +213,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["yaml-language-server"],
        method: Method::Npm { packages: &["yaml-language-server"] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/redhat-developer/yaml-language-server",
        needs: &[],
@@ -203,6 +224,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["vscode-json-language-server"],
        method: Method::Npm { packages: &["vscode-langservers-extracted"] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/hrsh7th/vscode-langservers-extracted",
        needs: &[],
@@ -213,6 +235,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["vscode-css-language-server"],
        method: Method::Npm { packages: &["vscode-langservers-extracted"] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/hrsh7th/vscode-langservers-extracted",
        needs: &[],
@@ -223,6 +246,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["vscode-html-language-server"],
        method: Method::Npm { packages: &["vscode-langservers-extracted"] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/hrsh7th/vscode-langservers-extracted",
        needs: &[],
@@ -233,6 +257,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["docker-langserver"],
        method: Method::Npm { packages: &["dockerfile-language-server-nodejs"] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/rcjsuen/dockerfile-language-server",
        needs: &[],
@@ -243,6 +268,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["svelteserver"],
        method: Method::Npm { packages: &["svelte-language-server", TYPESCRIPT] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/sveltejs/language-tools",
        needs: &[],
@@ -253,6 +279,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["vue-language-server"],
        method: Method::Npm { packages: &["@vue/language-server", TYPESCRIPT] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/vuejs/language-tools",
        needs: &[],
@@ -264,6 +291,7 @@ pub static TOOLS: &[ToolSpec] = &[
        commands: &["ngserver"],
        // Brings the TypeScript and `@angular/language-service` it loads.
        method: Method::Npm { packages: &["@angular/language-server"] },
+        fallback: None,
        version: V,
        homepage: "https://angular.dev/tools/language-service",
        needs: &[],
@@ -274,6 +302,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["graphql-lsp"],
        method: Method::Npm { packages: &["graphql-language-service-cli"] },
+        fallback: None,
        version: V,
        homepage: "https://github.com/graphql/graphiql",
        needs: &[],
@@ -284,6 +313,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["intelephense"],
        method: Method::Npm { packages: &["intelephense"] },
+        fallback: None,
        version: V,
        homepage: "https://intelephense.com",
        needs: &[],
@@ -294,6 +324,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["gopls"],
        method: Method::Go { module: "golang.org/x/tools/gopls@latest" },
+        fallback: None,
        version: Some(("gopls", &["version"])),
        homepage: "https://pkg.go.dev/golang.org/x/tools/gopls",
        needs: &[],
@@ -304,6 +335,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["sqls"],
        method: Method::Go { module: "github.com/sqls-server/sqls@latest" },
+        fallback: None,
        version: Some(("sqls", &["--version"])),
        homepage: "https://github.com/sqls-server/sqls",
        needs: &[],
@@ -314,6 +346,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: Debugger,
        commands: &["dlv"],
        method: Method::Go { module: "github.com/go-delve/delve/cmd/dlv@latest" },
+        fallback: None,
        version: Some(("dlv", &["version"])),
        homepage: "https://github.com/go-delve/delve",
        needs: &[],
@@ -324,6 +357,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: Debugger,
        commands: &["python3"],
        method: Method::PipTarget { package: "debugpy", module: "debugpy" },
+        fallback: None,
        version: V,
        homepage: "https://github.com/microsoft/debugpy",
        needs: &[],
@@ -342,6 +376,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["clangd"],
        },
+        fallback: None,
        version: ver("clangd"),
        homepage: "https://clangd.llvm.org",
        needs: &[],
@@ -362,6 +397,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["lua-language-server"],
        },
+        fallback: None,
        version: ver("lua-language-server"),
        homepage: "https://luals.github.io",
        needs: &[],
@@ -381,6 +417,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["marksman"],
        },
+        fallback: None,
        version: ver("marksman"),
        homepage: "https://github.com/artempyanykh/marksman",
        needs: &[],
@@ -401,6 +438,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["taplo"],
        },
+        fallback: None,
        version: ver("taplo"),
        homepage: "https://taplo.tamasfe.dev",
        needs: &[],
@@ -421,6 +459,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["zls"],
        },
+        fallback: None,
        version: ver("zls"),
        homepage: "https://github.com/zigtools/zls",
        needs: &[],
@@ -441,6 +480,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["terraform-ls"],
        },
+        fallback: None,
        version: Some(("terraform-ls", &["version"])),
        homepage: "https://github.com/hashicorp/terraform-ls",
        needs: &[],
@@ -466,6 +506,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["codelldb"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/vadimcn/codelldb",
        needs: &[],
@@ -485,6 +526,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["dapDebugServer.js"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/microsoft/vscode-js-debug",
        needs: &[],
@@ -503,6 +545,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["jdtls", "jdtls.bat"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/eclipse-jdtls/eclipse.jdt.ls",
        needs: &[],
@@ -522,6 +565,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["com.microsoft.java.debug.plugin-*.jar"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/microsoft/java-debug",
        needs: &[],
@@ -541,6 +585,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["lombok.jar"],
        },
+        fallback: None,
        version: V,
        homepage: "https://projectlombok.org",
        needs: &[],
@@ -565,6 +610,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["kotlin-lsp", "kotlin-lsp.sh", "kotlin-lsp.cmd"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/Kotlin/kotlin-lsp",
        needs: &[],
@@ -581,6 +627,7 @@ pub static TOOLS: &[ToolSpec] = &[
            assets: ELIXIR_LS_ASSETS,
            locate: &["language_server.sh", "language_server.bat"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/elixir-lsp/elixir-ls",
        needs: ELIXIR,
@@ -595,6 +642,7 @@ pub static TOOLS: &[ToolSpec] = &[
            assets: ELIXIR_LS_ASSETS,
            locate: &["debug_adapter.sh", "debug_adapter.bat"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/elixir-lsp/elixir-ls",
        needs: ELIXIR,
@@ -616,6 +664,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["buf"],
        },
+        fallback: None,
        version: ver("buf"),
        homepage: "https://buf.build",
        needs: &[],
@@ -636,6 +685,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["clojure-lsp"],
        },
+        fallback: None,
        version: V,
        homepage: "https://clojure-lsp.io",
        needs: &[],
@@ -657,6 +707,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["texlab"],
        },
+        fallback: None,
        version: ver("texlab"),
        homepage: "https://github.com/latex-lsp/texlab",
        needs: &[],
@@ -677,6 +728,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["neocmakelsp"],
        },
+        fallback: None,
        version: ver("neocmakelsp"),
        homepage: "https://github.com/Decodetalkers/neocmakelsp",
        needs: &[],
@@ -697,6 +749,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["lemminx-*"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/eclipse/lemminx",
        needs: &[],
@@ -715,6 +768,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["perlnavigator"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/bscan/PerlNavigator",
        needs: &[("perl", "Perl is required (https://www.perl.org/get.html)")],
@@ -729,6 +783,7 @@ pub static TOOLS: &[ToolSpec] = &[
            assets: &[any_arch(Mac, "server.zip"), any_arch(Linux, "server.zip"), any_arch(Windows, "server.zip")],
            locate: &["kotlin-language-server"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/fwcd/kotlin-language-server",
        needs: JAVA,
@@ -743,6 +798,7 @@ pub static TOOLS: &[ToolSpec] = &[
            assets: &[any_arch(Mac, "adapter.zip"), any_arch(Linux, "adapter.zip"), any_arch(Windows, "adapter.zip")],
            locate: &["kotlin-debug-adapter"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/fwcd/kotlin-debug-adapter",
        needs: JAVA,
@@ -762,6 +818,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["netcoredbg"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/Samsung/netcoredbg",
        needs: &[],
@@ -780,6 +837,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["bashDebug.js"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/rogalmic/vscode-bash-debug",
        needs: NODE,
@@ -798,6 +856,7 @@ pub static TOOLS: &[ToolSpec] = &[
            ],
            locate: &["phpDebug.js"],
        },
+        fallback: None,
        version: V,
        homepage: "https://github.com/xdebug/vscode-php-debug",
        needs: NODE,
@@ -808,6 +867,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["ruby-lsp"],
        method: Method::Gem { gem: "ruby-lsp" },
+        fallback: None,
        version: V,
        homepage: "https://shopify.github.io/ruby-lsp",
        needs: &[],
@@ -818,6 +878,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["solargraph"],
        method: Method::Gem { gem: "solargraph" },
+        fallback: None,
        version: ver("solargraph"),
        homepage: "https://solargraph.org",
        needs: &[],
@@ -828,6 +889,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["csharp-ls"],
        method: Method::DotnetTool { package: "csharp-ls" },
+        fallback: None,
        version: V,
        homepage: "https://github.com/razzmatazz/csharp-language-server",
        needs: &[],
@@ -838,6 +900,7 @@ pub static TOOLS: &[ToolSpec] = &[
        kind: LanguageServer,
        commands: &["fsautocomplete"],
        method: Method::DotnetTool { package: "fsautocomplete" },
+        fallback: None,
        version: V,
        homepage: "https://github.com/ionide/FsAutoComplete",
        needs: &[],
@@ -177,6 +177,8 @@ pub fn jdtls_download(version: &str, latest_txt: &str) -> IdeResult<Download> {
 #[derive(Deserialize)]
 struct VsxExtension {
    version: String,
+    #[serde(default)]
+    downloads: std::collections::BTreeMap<String, String>,
    files: VsxFiles,
 }

@@ -191,7 +193,22 @@ pub fn openvsx_latest_url(namespace: &str, extension: &str) -> String {
    format!("https://open-vsx.org/api/{namespace}/{extension}/latest")
 }

-/// The `.vsix` of an Open VSX `…/latest` response (platform-independent extensions only).
+/// Select platform metadata when the universal package does not match the asset rules.
+pub fn openvsx_platform_url(json: &str, rules: &[AssetRule], platform: Platform) -> IdeResult<Option<String>> {
+    let ext: VsxExtension =
+        serde_json::from_str(json).map_err(|e| proto(format!("unexpected Open VSX response: {e}")))?;
+    if select_asset(&[file_name(&ext.files.download)], rules, platform).is_some() {
+        return Ok(None);
+    }
+    let names: Vec<&str> = ext.downloads.values().map(|url| file_name(url)).collect();
+    let name = select_asset(&names, rules, platform)
+        .ok_or_else(|| IdeError::unavailable("No Open VSX package for this platform"))?;
+    let url = ext.downloads.values().find(|url| file_name(url) == name).expect("selected download");
+    let (metadata, _) = url.rsplit_once("/file/").ok_or_else(|| proto("unexpected Open VSX download URL"))?;
+    Ok(Some(metadata.to_string()))
+}
+
+/// The `.vsix` of an Open VSX `…/latest` response.
 pub fn openvsx_pick(json: &str, rules: &[AssetRule], platform: Platform) -> IdeResult<Download> {
    let ext: VsxExtension =
        serde_json::from_str(json).map_err(|e| proto(format!("unexpected Open VSX response: {e}")))?;
@@ -355,6 +372,56 @@ mod tests {
        assert!(openvsx_pick(&other, rules, LINUX).is_err());
    }

+    #[test]
+    fn openvsx_rust_analyzer_platform_packages() {
+        use crate::platform::{Arch, Os};
+        let crate::registry::Method::Release { assets, .. } = find("rust-analyzer").unwrap().fallback.unwrap() else {
+            panic!("expected release fallback")
+        };
+        let targets = [
+            (Os::Mac, Arch::Arm64, "darwin-arm64"),
+            (Os::Mac, Arch::X64, "darwin-x64"),
+            (Os::Linux, Arch::Arm64, "linux-arm64"),
+            (Os::Linux, Arch::X64, "linux-x64"),
+            (Os::Windows, Arch::Arm64, "win32-arm64"),
+            (Os::Windows, Arch::X64, "win32-x64"),
+        ];
+        let base = "https://open-vsx.org/api/rust-lang/rust-analyzer";
+        let downloads: serde_json::Map<String, serde_json::Value> = targets
+            .iter()
+            .map(|(_, _, target)| {
+                (
+                    target.to_string(),
+                    format!("{base}/{target}/1.0.0/file/rust-lang.rust-analyzer-1.0.0@{target}.vsix").into(),
+                )
+            })
+            .collect();
+        let universal = serde_json::json!({
+            "version": "1.0.0", "downloads": downloads,
+            "files": {"download": format!("{base}/1.0.0/file/rust-lang.rust-analyzer-1.0.0.vsix")}
+        })
+        .to_string();
+        for (os, arch, target) in targets {
+            let platform = Platform { os, arch };
+            assert_eq!(
+                openvsx_platform_url(&universal, assets, platform).unwrap(),
+                Some(format!("{base}/{target}/1.0.0"))
+            );
+            let json = serde_json::json!({
+                "version": "1.0.0",
+                "files": {
+                    "download": downloads[target],
+                    "sha256": format!("{base}/{target}/1.0.0/file/rust-lang.rust-analyzer-1.0.0@{target}.sha256")
+                }
+            })
+            .to_string();
+            let download = openvsx_pick(&json, assets, platform).unwrap();
+            assert!(download.name.ends_with(&format!("@{target}.vsix")));
+            assert!(download.checksum_url.unwrap().ends_with(&format!("@{target}.sha256")));
+        }
+        assert!(openvsx_platform_url(&universal.replace("downloads", "unused"), assets, MAC_ARM).is_err());
+    }
+
    #[test]
    fn maven_central() {
        let xml =
@@ -65,8 +65,8 @@ fn everything_missing_on_an_empty_system() {
    let ra = find(&list, "rust-analyzer");
    assert_eq!(ra.status, ToolStatus::Missing);
    assert_eq!(ra.languages, vec!["Rust".to_string()]);
-    assert!(!ra.can_install, "rustup is not on the fake PATH");
-    assert!(ra.unavailable_reason.as_deref().unwrap().contains("rustup"));
+    assert!(!ra.can_install, "curl is not on the fake PATH");
+    assert!(ra.unavailable_reason.as_deref().unwrap().contains("curl"));
    let vtsls = find(&list, "vtsls");
    assert!(vtsls.languages.iter().any(|l| l == "TypeScript"));
    assert!(vtsls.unavailable_reason.as_deref().unwrap().contains("npm"));
@@ -552,3 +552,74 @@ fn the_installing_request_can_still_cancel_its_shared_install() {
    assert!(slot.cancel.is_cancelled());
    release_install_slot("taplo", &slot);
 }
+
+#[cfg(unix)]
+#[test]
+fn rust_analyzer_selects_openvsx_without_rustup() {
+    let env = Env::new();
+    env.script(&env.sys, "curl", "exit 0");
+    let tools = env.tools();
+    let spec = registry::find("rust-analyzer").unwrap();
+    assert!(matches!(
+        tools.install_method(spec),
+        Method::Release { source: ReleaseSource::OpenVsx { namespace: "rust-lang", extension: "rust-analyzer" }, .. }
+    ));
+    let info = tools.info("rust-analyzer", &langs()).unwrap();
+    assert_eq!(info.status, ToolStatus::Missing);
+    assert_eq!(info.install_method.as_deref(), Some("Open VSX"));
+    assert!(info.can_install);
+    assert!(info.unavailable_reason.is_none());
+    assert!(bin_dirs_in(&env.root, Platform::current()).contains(&env.root.join("rust-analyzer/bin")));
+}
+
+#[cfg(unix)]
+static RUST_ANALYZER_INSTALL: parking_lot::Mutex<()> = parking_lot::Mutex::new(());
+
+#[cfg(unix)]
+#[test]
+fn rust_analyzer_prefers_rustup_and_installs_component() {
+    let _guard = RUST_ANALYZER_INSTALL.lock();
+    let env = Env::new();
+    env.script(&env.sys, "rustup", "test \"$*\" = 'component add rust-analyzer'");
+    env.script(&env.sys, "rust-analyzer", "echo 'rust-analyzer 1.0.0'");
+    let tools = env.tools();
+    assert!(matches!(
+        tools.install_method(registry::find("rust-analyzer").unwrap()),
+        Method::Rustup { component: "rust-analyzer" }
+    ));
+    let info = tools.info("rust-analyzer", &langs()).unwrap();
+    assert_eq!(info.install_method.as_deref(), Some("rustup"));
+    assert!(info.can_install, "rustup does not require curl");
+    let mut lines = Vec::new();
+    let emit = parking_lot::Mutex::new(&mut lines);
+    tools
+        .install("rust-analyzer", &langs(), &CancellationToken::new(), &|event| {
+            if let InstallEvent::Line { text } = event {
+                emit.lock().push(text);
+            }
+        })
+        .unwrap();
+    assert!(lines.iter().any(|line| line.contains("via rustup")));
+}
+
+#[cfg(unix)]
+#[test]
+fn rust_analyzer_managed_copy_survives_rustup_becoming_available() {
+    let _guard = RUST_ANALYZER_INSTALL.lock();
+    let env = Env::new();
+    let bin = env.root.join("rust-analyzer/bin");
+    env.script(&bin, "rust-analyzer", "echo 'rust-analyzer 1.0.0'");
+    for with_rustup in [false, true] {
+        if with_rustup {
+            env.script(&env.sys, "rustup", "exit 1");
+            env.script(&env.sys, "rust-analyzer", "exit 1");
+        }
+        let info = env.tools().info("rust-analyzer", &langs()).unwrap();
+        assert_eq!(info.status, ToolStatus::Installed);
+        assert_eq!(info.path.as_deref(), Some(bin.join("rust-analyzer").as_path()));
+        assert_eq!(info.install_method.as_deref(), Some("Open VSX"), "Reinstall refreshes the copy in use");
+        assert!(info.can_uninstall);
+    }
+    env.tools().uninstall("rust-analyzer", &langs()).unwrap();
+    assert!(!env.root.join("rust-analyzer").exists());
+}