resolver: keep forward slashes when imports target is a package specifier

src/crash_handler/lib.rs

@@ -1766,7 +1766,12 @@ mod draft {
                     .store(handle as *mut core::ffi::c_void, Ordering::Relaxed);
             }
         }
-        #[cfg(any(target_os = "macos", target_os = "linux", target_os = "android", target_os = "freebsd"))]
+        #[cfg(any(
+            target_os = "macos",
+            target_os = "linux",
+            target_os = "android",
+            target_os = "freebsd"
+        ))]
         {
             reset_on_posix();
         }
@@ -2907,7 +2912,12 @@ mod draft {
             let _ = spawn_result;
             let _ = url;
         }
-        #[cfg(any(target_os = "macos", target_os = "linux", target_os = "android", target_os = "freebsd"))]
+        #[cfg(any(
+            target_os = "macos",
+            target_os = "linux",
+            target_os = "android",
+            target_os = "freebsd"
+        ))]
         {
             let mut buf = bun_core::PathBuffer::default();
             let mut buf2 = bun_core::PathBuffer::default();

src/errno/lib.rs

@@ -409,7 +409,12 @@ mod errno_name_tests {
         assert_eq!(Error::from_errno(0), Error::UNEXPECTED);
         assert_eq!(Error::from_errno(9999), Error::UNEXPECTED);
         // errno 11 is platform-specific: EAGAIN on linux/windows, EDEADLK on darwin/bsd.
-        #[cfg(any(target_os = "linux", target_os = "android", windows, target_family = "wasm"))]
+        #[cfg(any(
+            target_os = "linux",
+            target_os = "android",
+            windows,
+            target_family = "wasm"
+        ))]
         {
             assert_eq!(Error::from_errno(11), Error::intern("EAGAIN"));
             assert_eq!(Error::from_errno(104), Error::intern("ECONNRESET"));
@@ -464,7 +469,12 @@ mod errno_name_tests {
             coreutils_error_map::get(2),
             Some("No such file or directory")
         );
-        #[cfg(any(target_os = "linux", target_os = "android", windows, target_family = "wasm"))]
+        #[cfg(any(
+            target_os = "linux",
+            target_os = "android",
+            windows,
+            target_family = "wasm"
+        ))]
         assert_eq!(
             coreutils_error_map::get(11),
             Some("Resource temporarily unavailable")

src/perf/tracy.rs

@@ -756,7 +756,12 @@ fn dlsym<T: Copy>(symbol: &'static core::ffi::CStr) -> Option<T> {
                 ];
                 #[cfg(windows)]
                 const PATHS_TO_TRY: &[&core::ffi::CStr] = &[c"tracy.dll"];
-                #[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "android", windows)))]
+                #[cfg(not(any(
+                    target_os = "macos",
+                    target_os = "linux",
+                    target_os = "android",
+                    windows
+                )))]
                 const PATHS_TO_TRY: &[&core::ffi::CStr] = &[];
 
                 // TODO(port): RTLD flags — Zig used `@bitCast(@as(i32, -2))` on

src/resolver/package_json.rs

@@ -2758,9 +2758,17 @@ impl<'a> ESModule<'a> {
                                 },
                             };
                         } else {
+                            // PORT NOTE: Zig used `.auto` here, carried over as a
+                            // latent Windows bug (#30839): this branch runs when an
+                            // `imports` target is itself a package specifier
+                            // (e.g. `@myproject/resolver`) that we hand back to
+                            // package-resolve. Per the Node.js packages spec these
+                            // are URL-like specifiers and must keep forward slashes;
+                            // `Auto` normalizes them to `\` on Windows and the
+                            // scoped-name match fails, falling through to `main`.
                             let parts2 = [str, subpath];
                             let result = resolve_path::resolve_path::join_string_buf::<
-                                resolve_path::platform::Auto,
+                                resolve_path::platform::Posix,
                             >(
                                 &mut resolve_target_buf2.0, &parts2
                             );

src/runtime/cli/Arguments.rs

@@ -679,7 +679,10 @@ pub const BASE_RUNTIME_TRANSPILER_PARAMS: &[ParamType] =
 // built with `comptime_table!(.., cold)` and stay in plain `.rodata`, where
 // `src/startup.order` can still cluster the ones a sampled cold path actually
 // hits without weighing down the `.rodata.startup` fault-around window.
-#[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".rodata.startup"))]
+#[cfg_attr(
+    any(target_os = "linux", target_os = "android"),
+    unsafe(link_section = ".rodata.startup")
+)]
 pub static AUTO_TABLE: &clap::ConvertedTable = clap::comptime_table!(AUTO_PARAMS);
 pub static RUN_TABLE: &clap::ConvertedTable = clap::comptime_table!(RUN_PARAMS, cold);
 pub static BUILD_TABLE: &clap::ConvertedTable = clap::comptime_table!(BUILD_PARAMS, cold);

src/runtime/cli/run_command.rs

@@ -552,7 +552,10 @@ Full documentation is available at <magenta>https://bun.com/docs/cli/run<r>
     /// not share `.text` pages with the hot `bun run <script>` dispatch path.
     #[cold]
     #[inline(never)]
-    #[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+    #[cfg_attr(
+        any(target_os = "linux", target_os = "android"),
+        unsafe(link_section = ".text.unlikely")
+    )]
     fn configure_run_transpiler_linker(this_transpiler: &mut Transpiler<'static>) {
         this_transpiler.resolver.opts.load_tsconfig_json = true;
         this_transpiler.options.load_tsconfig_json = true;
@@ -870,7 +873,10 @@ Full documentation is available at <magenta>https://bun.com/docs/cli/run<r>
     /// initializing JSC.
     #[cold]
     #[inline(never)]
-    #[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+    #[cfg_attr(
+        any(target_os = "linux", target_os = "android"),
+        unsafe(link_section = ".text.unlikely")
+    )]
     fn boot_bun_shell(
         ctx: &mut ContextData,
         entry_path: &[u8],
@@ -1669,7 +1675,10 @@ fn log_clear_msgs(vm: &mut VirtualMachine) {
 
 #[cold]
 #[inline(never)]
-#[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+#[cfg_attr(
+    any(target_os = "linux", target_os = "android"),
+    unsafe(link_section = ".text.unlikely")
+)]
 fn dump_build_error(vm: &mut VirtualMachine) {
     Output::flush();
     if let Some(log) = vm.log {
@@ -1689,7 +1698,10 @@ fn dump_build_error(vm: &mut VirtualMachine) {
 /// `.text.hot` fault-around window the `require('fs')` startup path pulls in.
 #[cold]
 #[inline(never)]
-#[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+#[cfg_attr(
+    any(target_os = "linux", target_os = "android"),
+    unsafe(link_section = ".text.unlikely")
+)]
 fn exit_with_unhandled_note(vm: &mut VirtualMachine) -> ! {
     vm.exit_handler.exit_code = 1;
     vm.on_exit();
@@ -1703,7 +1715,10 @@ fn exit_with_unhandled_note(vm: &mut VirtualMachine) -> ! {
 /// Cold `Err(err)` arm of `vm.load_entry_point` in `Run::start`.
 #[cold]
 #[inline(never)]
-#[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+#[cfg_attr(
+    any(target_os = "linux", target_os = "android"),
+    unsafe(link_section = ".text.unlikely")
+)]
 fn entry_point_load_failed(vm: &mut VirtualMachine, err: &bun_core::Error) -> ! {
     if log_has_msgs(vm) {
         dump_build_error(vm);
@@ -1722,7 +1737,10 @@ fn entry_point_load_failed(vm: &mut VirtualMachine, err: &bun_core::Error) -> !
 /// exit: bump the exit code and print the sourcemap note + version string.
 #[cold]
 #[inline(never)]
-#[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+#[cfg_attr(
+    any(target_os = "linux", target_os = "android"),
+    unsafe(link_section = ".text.unlikely")
+)]
 fn print_unhandled_version_note(vm: &mut VirtualMachine) {
     vm.exit_handler.exit_code = 1;
     bun_sourcemap::SavedSourceMap::MissingSourceMapNoteInfo::print();
@@ -1762,7 +1780,10 @@ impl RunCommand {
     /// `.text.hot` fault-around window the `require('fs')` startup path pulls in.
     #[cold]
     #[inline(never)]
-    #[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+    #[cfg_attr(
+        any(target_os = "linux", target_os = "android"),
+        unsafe(link_section = ".text.unlikely")
+    )]
     fn boot_failed_exit(ctx: &mut ContextData, display_name: &[u8], err: &bun_core::Error) -> ! {
         // SAFETY: `ctx.log` was set in `create_context_data` (single-threaded
         // CLI startup) and is process-lifetime.
@@ -3022,7 +3043,10 @@ impl RunCommand {
 
     #[cold]
     #[inline(never)]
-    #[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+    #[cfg_attr(
+        any(target_os = "linux", target_os = "android"),
+        unsafe(link_section = ".text.unlikely")
+    )]
     fn exec_as_if_node_missing_script() -> ! {
         Output::err_generic(
             "Missing script to execute. Bun's provided 'node' cli wrapper does not support a repl.",
@@ -3033,7 +3057,10 @@ impl RunCommand {
 
     #[cold]
     #[inline(never)]
-    #[cfg_attr(any(target_os = "linux", target_os = "android"), unsafe(link_section = ".text.unlikely"))]
+    #[cfg_attr(
+        any(target_os = "linux", target_os = "android"),
+        unsafe(link_section = ".text.unlikely")
+    )]
     fn exec_as_if_node_boot_failed(
         ctx: &mut ContextData,
         basename: &[u8],

src/runtime/cli/upgrade_command.rs

@@ -515,7 +515,12 @@ impl UpgradeCommand {
         {
             "powershell -c 'irm bun.sh/install.ps1|iex'"
         }
-        #[cfg(not(any(target_os = "linux", target_os = "android", target_os = "macos", target_os = "windows")))]
+        #[cfg(not(any(
+            target_os = "linux",
+            target_os = "android",
+            target_os = "macos",
+            target_os = "windows"
+        )))]
         {
             // TODO(port): Environment.os.displayString() at comptime
             "(TODO: Install script for this platform)"

src/runtime/jsc_hooks.rs

@@ -4499,13 +4499,14 @@ pub(crate) fn resolve_embedded_file_to_buf(
     // Spec ModuleLoader.zig:43-45 — `tmpname(extname, buf, bun.hash(file.name))`.
     let mut tmpname_buf = bun_paths::path_buffer_pool::get();
     let tmpfilename =
-        Fs::FileSystem::tmpname(extname, &mut tmpname_buf[..], bun_wyhash::hash(file_name))
-            .ok()?;
+        Fs::FileSystem::tmpname(extname, &mut tmpname_buf[..], bun_wyhash::hash(file_name)).ok()?;
 
     // Spec ModuleLoader.zig:47 — `bun.fs.FileSystem.instance.tmpdir()`.
     // SAFETY: `FileSystem::instance()` returns the process-global singleton
     // pointer (initialized at startup).
-    let tmpdir = (unsafe { &mut *Fs::FileSystem::instance() }).tmpdir().ok()?;
+    let tmpdir = (unsafe { &mut *Fs::FileSystem::instance() })
+        .tmpdir()
+        .ok()?;
     let tmpdir_fd: bun_sys::Fd = tmpdir.fd;
 
     // Spec ModuleLoader.zig:50-51 — `bun.Tmpfile.create(tmpdir, tmpfilename)`.

src/runtime/webview/ChromeProcess.rs

@@ -358,7 +358,10 @@ fn find_playwright_shell() -> Option<ZBox> {
     }
 
     // Fall back to the non-cft linux arm64 layout.
-    #[cfg(all(any(target_os = "linux", target_os = "android"), target_arch = "aarch64"))]
+    #[cfg(all(
+        any(target_os = "linux", target_os = "android"),
+        target_arch = "aarch64"
+    ))]
     {
         let bin_parts2: [&[u8]; 3] = [
             cache_dir,
@@ -633,7 +636,12 @@ fn read_dev_tools_active_port(out_buf: &mut Vec<u8>) -> Option<()> {
         b"BraveSoftware\\Brave-Browser\\User Data\\DevToolsActivePort",
         b"Microsoft\\Edge\\User Data\\DevToolsActivePort",
     ];
-    #[cfg(not(any(target_os = "macos", target_os = "linux", target_os = "android", windows)))]
+    #[cfg(not(any(
+        target_os = "macos",
+        target_os = "linux",
+        target_os = "android",
+        windows
+    )))]
     let candidates: &[&[u8]] = &[];
 
     let mut path_buf = path_buffer_pool::get();

src/spawn/process.rs

@@ -3224,7 +3224,10 @@ mod spawn_process_body {
             // that are read *after* the wait, so falling through to the memfd block
             // below is required.
             let status: Status = 'blk: {
-                if no_orphans && (cfg!(any(target_os = "linux", target_os = "android")) || cfg!(target_os = "macos")) {
+                if no_orphans
+                    && (cfg!(any(target_os = "linux", target_os = "android"))
+                        || cfg!(target_os = "macos"))
+                {
                     let ppid = ParentDeathWatchdog::ppid_to_watch().unwrap_or(0);
                     #[cfg(target_os = "macos")]
                     let r: Option<Maybe<Status>> = wait_mac_kqueue(
@@ -3245,7 +3248,11 @@ mod spawn_process_body {
                         &mut out_fds_to_wait_for,
                         &mut out_fds,
                     );
-                    #[cfg(not(any(target_os = "linux", target_os = "android", target_os = "macos")))]
+                    #[cfg(not(any(
+                        target_os = "linux",
+                        target_os = "android",
+                        target_os = "macos"
+                    )))]
                     let r: Option<Maybe<Status>> = {
                         let _ = ppid;
                         None

src/spawn_sys/spawn_process.rs

@@ -775,7 +775,10 @@ pub fn spawn_process_posix(
     let mut dup_stdout_to_stderr: bool = false;
 
     // The label is only referenced from the Linux memfd fast-path below.
-    #[cfg_attr(not(any(target_os = "linux", target_os = "android")), allow(unused_labels))]
+    #[cfg_attr(
+        not(any(target_os = "linux", target_os = "android")),
+        allow(unused_labels)
+    )]
     'stdio: for i in 0..3usize {
         let fileno = Fd::from_native(FdT::try_from(i).unwrap());
         let flag: u32 = (if i == 0 {

test/js/bun/resolve/resolve.test.ts

@@ -1,6 +1,6 @@
 import { pathToFileURL } from "bun";
 import { describe, expect, it } from "bun:test";
-import { chmodSync, chownSync, mkdirSync, readFileSync, writeFileSync } from "fs";
+import { chmodSync, chownSync, mkdirSync, readFileSync, symlinkSync, writeFileSync } from "fs";
 import { bunEnv, bunExe, bunRun, isLinux, isWindows, joinP, tempDir, tempDirWithFiles } from "harness";
 import { join, resolve, sep } from "path";
 
@@ -589,6 +589,64 @@ describe("wildcard exports with @ in matched subpath", () => {
   });
 });
 
+// A package.json `imports` entry whose value is a bare package specifier
+// (e.g. `"#res": "@myproject/resolver"`) is handed back to package-resolve
+// for a second pass. Per the Node.js packages spec these are URL-like
+// specifiers and must always use forward slashes. On Windows, the join that
+// feeds the second pass was going through `platform::Auto` which normalizes
+// `/` to `\`, turning `@myproject/resolver` into `@myproject\resolver` —
+// the scoped-package match fails and Bun falls back to the legacy `main`
+// field instead of `exports`. Linux/macOS aren't affected because `Auto`
+// is already `Posix` there; this test is therefore Windows-only.
+// https://github.com/oven-sh/bun/issues/30839
+describe.if(isWindows)("#30839 - imports entry pointing at a scoped package", () => {
+  it("resolves via the target's exports, not its main", async () => {
+    using dir = tempDir("resolver-imports-scoped-pkg", {
+      "package.json": JSON.stringify({ name: "root", private: true, workspaces: ["packages/*"] }),
+      "packages/resolver/package.json": JSON.stringify({
+        name: "@myproject/resolver",
+        type: "module",
+        main: "./index.cjs",
+        exports: { ".": "./index.mjs" },
+      }),
+      "packages/resolver/index.mjs": "export const type = 'esm (from exports)';",
+      "packages/resolver/index.cjs": "module.exports = { type: 'cjs (from main)' };",
+      "packages/app/package.json": JSON.stringify({
+        name: "app",
+        type: "module",
+        dependencies: { "@myproject/resolver": "workspace:*" },
+        imports: { "#res": "@myproject/resolver" },
+      }),
+      "packages/app/test.mjs": `import { type } from "#res";\nconsole.log(type);`,
+    });
+    const root = String(dir);
+
+    // Wire up @myproject/resolver into app/node_modules so the second pass
+    // through the resolver (the one this fix repairs) can find it — without
+    // invoking `bun install`. `"junction"` is the Windows-appropriate symlink
+    // kind for directories.
+    mkdirSync(join(root, "packages/app/node_modules/@myproject"), { recursive: true });
+    symlinkSync(
+      join(root, "packages/resolver"),
+      join(root, "packages/app/node_modules/@myproject/resolver"),
+      "junction",
+    );
+
+    await using proc = Bun.spawn({
+      cmd: [bunExe(), "test.mjs"],
+      env: bunEnv,
+      cwd: join(root, "packages/app"),
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+
+    expect(stderr).toBe("");
+    expect(stdout).toBe("esm (from exports)\n");
+    expect(exitCode).toBe(0);
+  });
+});
+
 // dirInfoCachedMaybeLog reads the rfs.entries cache without checking the union
 // tag. If readDirectory() previously failed with a non-ENOENT error (e.g.
 // EACCES), a `.err` variant is stored there; re-resolving the directory after