0.37.1: fix folder-download hang/501 on special files + add download progress

Two issues with the 0.37.0 folder zip-download:

1. Hang / server error (reported as 501) on "some folders". archive_dir
   tried to zip every entry, including non-regular files. Opening a FIFO
   blocks forever (no writer); a unix socket / unreadable file raised an
   OSError that aborted the whole archive. Now only real regular files are
   zipped — FIFOs, sockets, devices and symlinks are skipped without ever
   open()-ing them, and a per-file read error skips just that file instead
   of failing the download.

2. No feedback while a large folder is being prepared. The zip is built
   server-side before any bytes flow, so the click felt dead. The Files
   page now shows an indeterminate "Preparing <name>…" bar from click,
   switching to a real percentage during the transfer (Content-Length is
   known for the finished zip). filesApi.download forwards onDownloadProgress.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/services/file_service.py

@@ -187,7 +187,13 @@ def archive_dir(path: str) -> tuple[str, str]:
 
     Returns ``(tmp_zip_path, download_filename)``. The caller is responsible
     for deleting the temp file once it has been streamed to the client.
-    Symlinks are skipped so the archive cannot escape the sandbox or loop.
+
+    Only regular files and real subdirectories are archived. Symlinks are
+    skipped (no sandbox escape / loops); special files (FIFOs, sockets,
+    devices) are skipped too — opening a FIFO would block forever and a
+    socket can't be read at all. Files that can't be read (permissions, or
+    that vanish mid-walk) are skipped individually rather than aborting the
+    whole archive.
     """
     real = _safe_real(path)
     if not os.path.isdir(real):
@@ -207,10 +213,18 @@ def archive_dir(path: str) -> tuple[str, str]:
                     zf.writestr(os.path.join(name, rel_root) + "/", "")
                 for f in files:
                     full = os.path.join(root, f)
-                    if os.path.islink(full):
+                    # os.path.isfile follows symlinks; combined with the islink
+                    # check it admits only real regular files (skips FIFOs,
+                    # sockets, devices and symlinks without ever open()-ing them).
+                    if os.path.islink(full) or not os.path.isfile(full):
+                        continue
+                    arc = (os.path.join(name, rel_root, f) if rel_root != "."
+                           else os.path.join(name, f))
+                    try:
+                        zf.write(full, arc)
+                    except OSError:
+                        # Unreadable or vanished mid-walk — skip just this file.
                         continue
-                    zf.write(full, os.path.join(name, rel_root, f) if rel_root != "."
-                             else os.path.join(name, f))
     except OSError:
         if os.path.exists(tmp):
             os.unlink(tmp)

backend/version.py

@@ -1,3 +1,3 @@
 """Single source of truth for the StackPilot release version."""
 
-APP_VERSION = "0.37.0"
+APP_VERSION = "0.37.1"

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "stackpilot-frontend",
   "private": true,
-  "version": "0.37.0",
+  "version": "0.37.1",
   "type": "module",
   "scripts": {
     "dev": "vite",

frontend/src/api/files.ts

@@ -58,8 +58,19 @@ export const filesApi = {
       .post<{ path: string }>(`${base(agentId)}/move`, { src, dest_dir: destDir, overwrite })
       .then((r) => r.data),
 
-  download: async (path: string, filename: string, agentId?: number) => {
+  download: async (
-    const res = await api.get(`${base(agentId)}/download`, { params: { path }, responseType: "blob" });
+    path: string,
+    filename: string,
+    agentId?: number,
+    onProgress?: (loaded: number, total: number | undefined) => void,
+  ) => {
+    const res = await api.get(`${base(agentId)}/download`, {
+      params: { path },
+      responseType: "blob",
+      onDownloadProgress: onProgress
+        ? (e) => onProgress(e.loaded, e.total || undefined)
+        : undefined,
+    });
     triggerDownload(res.data as Blob, filename);
   },
 

frontend/src/pages/Files.tsx

@@ -83,7 +83,12 @@ export function Files() {
   const [newKind, setNewKind] = useState<"dir" | "file" | null>(null);
   const [clip, setClip] = useState<Clipboard | null>(null);
   const [pasteConflict, setPasteConflict] = useState(false);
-  const [progress, setProgress] = useState<{ label: string; pct: number } | null>(null);
+  const [progress, setProgress] = useState<{
+    label: string;
+    pct: number;
+    kind: "upload" | "download";
+    indeterminate?: boolean;
+  } | null>(null);
   const fileInput = useRef<HTMLInputElement>(null);
   const folderInput = useRef<HTMLInputElement>(null);
 
@@ -111,9 +116,9 @@ export function Files() {
 
   const upload = useMutation({
     mutationFn: (file: File) => {
-      setProgress({ label: file.name, pct: 0 });
+      setProgress({ label: file.name, pct: 0, kind: "upload" });
       return filesApi.upload(path, file, false, "", host, (pct) =>
-        setProgress({ label: file.name, pct })
+        setProgress({ label: file.name, pct, kind: "upload" })
       );
     },
     onSuccess: (r) => {
@@ -149,6 +154,7 @@ export function Files() {
             setProgress({
               label: `${f.name} (${i + 1}/${total})`,
               pct: ((i + filePct / 100) / total) * 100,
+              kind: "upload",
             })
           );
           ok += 1;
@@ -200,10 +206,27 @@ export function Files() {
     onError: (e) => toast.error(apiErrorMessage(e)),
   });
 
-  const download = (e: HostPathEntry) =>
+  const download = (e: HostPathEntry) => {
-    filesApi
+    const isDir = e.type === "dir";
-      .download(join(path, e.name), e.type === "dir" ? `${e.name}.zip` : e.name, host)
+    // Folders are zipped server-side first (no bytes yet) — start with an
-      .catch((err) => toast.error(apiErrorMessage(err)));
+    // indeterminate "Preparing…" bar, then switch to % once data flows.
+    setProgress({ label: e.name, pct: 0, kind: "download", indeterminate: true });
+    return filesApi
+      .download(
+        join(path, e.name),
+        isDir ? `${e.name}.zip` : e.name,
+        host,
+        (loaded, total) =>
+          setProgress({
+            label: e.name,
+            pct: total ? (loaded / total) * 100 : 0,
+            kind: "download",
+            indeterminate: !total,
+          }),
+      )
+      .catch((err) => toast.error(apiErrorMessage(err)))
+      .finally(() => setProgress(null));
+  };
 
   return (
     <div className="space-y-4">
@@ -294,21 +317,37 @@ export function Files() {
         </div>
       </div>
 
-      {/* Upload progress */}
+      {/* Upload / download progress */}
       {progress && (
         <div className="space-y-1">
           <div className="flex items-center justify-between gap-2 text-xs text-slate-500">
             <span className="flex min-w-0 items-center gap-1.5">
-              <Upload className="h-3.5 w-3.5 shrink-0" />
+              {progress.kind === "download" ? (
-              <span className="truncate">Uploading {progress.label}</span>
+                <Download className="h-3.5 w-3.5 shrink-0" />
+              ) : (
+                <Upload className="h-3.5 w-3.5 shrink-0" />
+              )}
+              <span className="truncate">
+                {progress.kind === "download"
+                  ? progress.indeterminate
+                    ? `Preparing ${progress.label}…`
+                    : `Downloading ${progress.label}`
+                  : `Uploading ${progress.label}`}
+              </span>
+            </span>
+            <span className="tabular-nums">
+              {progress.indeterminate ? "" : `${Math.round(progress.pct)}%`}
             </span>
-            <span className="tabular-nums">{Math.round(progress.pct)}%</span>
           </div>
           <div className="h-2 w-full overflow-hidden rounded-full bg-slate-200 dark:bg-slate-700">
-            <div
+            {progress.indeterminate ? (
-              className="h-full rounded-full bg-accent transition-all dark:bg-accent-dark"
+              <div className="h-full w-1/3 animate-indeterminate rounded-full bg-accent dark:bg-accent-dark" />
-              style={{ width: `${progress.pct}%` }}
+            ) : (
-            />
+              <div
+                className="h-full rounded-full bg-accent transition-all dark:bg-accent-dark"
+                style={{ width: `${progress.pct}%` }}
+              />
+            )}
           </div>
         </div>
       )}

frontend/tailwind.config.ts

@@ -37,6 +37,16 @@ export default {
         pill: "var(--sp-r-pill)",
         chip: "var(--sp-r-chip)",
       },
+      keyframes: {
+        // Sliding bar for indeterminate progress (e.g. server zipping a folder).
+        indeterminate: {
+          "0%": { transform: "translateX(-100%)" },
+          "100%": { transform: "translateX(400%)" },
+        },
+      },
+      animation: {
+        indeterminate: "indeterminate 1.2s ease-in-out infinite",
+      },
     },
   },
   plugins: [],