install(isolated): link bins of -g update requests into $BUN_INSTALL/bin

src/install/isolated_install/Installer.rs

@@ -2307,6 +2307,11 @@ impl<'a> Installer<'a> {
             Which::Staging,
         );
 
+        // `bun add -g`: root-level update requests link into `options.bin_path`
+        // (~/.bun/bin); everything else stays in the parent's local `.bin/`.
+        let link_into_global_bin =
+            self.manager().options.global && parent_entry_id == StoreEntryId::ROOT;
+
         for dep in entry_deps[parent_entry_id.get() as usize].slice() {
             let node_id = entry_node_ids[dep.entry_id.get() as usize];
             let dep_id = node_dep_ids[node_id.get() as usize];
@@ -2347,6 +2352,19 @@ impl<'a> Installer<'a> {
                 );
             }
 
+            let global = if !link_into_global_bin {
+                false
+            } else {
+                'global: {
+                    for request in self.manager().update_requests.iter() {
+                        if request.package_id == pkg_id {
+                            break 'global true;
+                        }
+                    }
+                    break 'global false;
+                }
+            };
+
             // see the matching note in `Step::LinkBinaries` —
             // `target_node_modules_path` may alias `node_modules_path` and
             // the Linker field is a raw `*const AbsPath` to permit that.
@@ -2375,7 +2393,7 @@ impl<'a> Installer<'a> {
                 skipped_due_to_missing_bin: false,
             };
 
-            bin_linker.link(false);
+            bin_linker.link(global);
 
             if target_node_modules_path.is_some()
                 && (bin_linker.skipped_due_to_missing_bin || bin_linker.err.is_some())
@@ -2391,7 +2409,7 @@ impl<'a> Installer<'a> {
                     );
                 }
 
-                bin_linker.link(false);
+                bin_linker.link(global);
             }
 
             if let Some(err) = bin_linker.err {

test/cli/install/isolated-install.test.ts

@@ -3018,3 +3018,83 @@ describe("hoist", () => {
     );
   });
 });
+
+describe("global install", () => {
+  // Regression: `bun add -g --linker isolated <pkg-with-bin>` used to leave
+  // the bin in `<BUN_INSTALL>/install/global/node_modules/.bin/` instead of
+  // linking it into `<BUN_INSTALL>/bin/`, so the command wasn't on $PATH.
+  // https://github.com/oven-sh/bun/issues/30450
+  //
+  // File-path deps here so the test doesn't depend on the registry — the bug
+  // is in the isolated installer's `linkDependencyBins` pass and fires the
+  // same way regardless of source.
+  test("links requested-package bins into BUN_INSTALL/bin", async () => {
+    using dir = tempDir("isolated-global-bin-", {
+      "pkg-with-bin/package.json": JSON.stringify({
+        name: "pkg-with-bin",
+        version: "1.0.0",
+        bin: { "bin-from-pkg": "./cli.js" },
+      }),
+      "pkg-with-bin/cli.js": "#!/usr/bin/env node\nconsole.log('ok');\n",
+    });
+    const bunInstall = join(String(dir), "bun-install");
+    const globalBinDir = join(bunInstall, "bin");
+
+    await using proc = spawn({
+      cmd: [bunExe(), "add", "-g", "--linker=isolated", join(String(dir), "pkg-with-bin")],
+      cwd: String(dir),
+      env: { ...bunEnv, BUN_INSTALL: bunInstall },
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+    expect(stderr).not.toContain("error:");
+    expect(stdout).toContain("pkg-with-bin");
+    expect(exitCode).toBe(0);
+
+    // POSIX: `bin-from-pkg` symlink. Windows: `bin-from-pkg.exe` shim.
+    const hasBin = existsSync(join(globalBinDir, "bin-from-pkg")) || existsSync(join(globalBinDir, "bin-from-pkg.exe"));
+    expect(hasBin).toBe(true);
+  });
+
+  // A *non-global* `bun install` must never link bins into `<BUN_INSTALL>/bin/`
+  // — the global-bin link is gated on `options.global`. A local install with
+  // the isolated linker puts the bin in the project's `node_modules/.bin/` only.
+  // Guards the `options.global` half of the gate.
+  test("non-global install does not link bins into BUN_INSTALL/bin", async () => {
+    using dir = tempDir("isolated-global-bin-local-", {
+      "proj/package.json": JSON.stringify({
+        name: "proj",
+        version: "1.0.0",
+        dependencies: { "dep-pkg": "file:../dep-pkg" },
+      }),
+      "proj/bunfig.toml": `[install]\nlinker = "isolated"\n`,
+      "dep-pkg/package.json": JSON.stringify({
+        name: "dep-pkg",
+        version: "1.0.0",
+        bin: { "dep-bin": "./dep.js" },
+      }),
+      "dep-pkg/dep.js": "#!/usr/bin/env node\nconsole.log('dep');\n",
+    });
+    const projDir = join(String(dir), "proj");
+    const bunInstall = join(String(dir), "bun-install");
+    const globalBinDir = join(bunInstall, "bin");
+
+    await using proc = spawn({
+      cmd: [bunExe(), "install"],
+      cwd: projDir,
+      env: { ...bunEnv, BUN_INSTALL: bunInstall },
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+    expect(stderr).not.toContain("error:");
+    expect(exitCode).toBe(0);
+
+    // The bin is linked into the project, not the global bin dir.
+    const localBin = process.platform === "win32" ? "dep-bin.bunx" : "dep-bin";
+    expect(existsSync(join(projDir, "node_modules", ".bin", localBin))).toBe(true);
+    expect(existsSync(join(globalBinDir, "dep-bin"))).toBe(false);
+    expect(existsSync(join(globalBinDir, "dep-bin.exe"))).toBe(false);
+  });
+});