fix(windows): handle read-only git pack files causing WinError 5 on amplifier update

amplifier_app_cli/commands/reset.py

@@ -20,13 +20,13 @@
 
 from __future__ import annotations
 
-import shutil
 import subprocess
 from pathlib import Path
 
 import click
 
 from ..console import console
+from ..utils.cache_management import rmtree_safe
 from ..utils.error_format import escape_markup
 from ..utils.uv_utils import remove_stale_uv_lock as _remove_stale_uv_lock
 from .reset_interactive import ChecklistItem, run_checklist
@@ -302,7 +302,7 @@ def _remove_amplifier_dir(preserve: set[str], dry_run: bool = False) -> bool:
             return True
 
         try:
-            shutil.rmtree(amplifier_dir)
+            rmtree_safe(amplifier_dir)
             console.print("    [green]Removed entire directory[/green]")
             return True
         except OSError as e:
@@ -339,7 +339,7 @@ def _remove_amplifier_dir(preserve: set[str], dry_run: bool = False) -> bool:
                     else:
                         # Standard removal (fallback or other items)
                         if item.is_dir():
-                            shutil.rmtree(item)
+                            rmtree_safe(item)
                         else:
                             item.unlink()
                         removed_count += 1

amplifier_app_cli/lib/sources_compat.py

@@ -215,7 +215,7 @@ async def install_to(self, target_dir: Path) -> None:
         Raises:
             InstallError: Git clone failed
         """
-        import shutil
+        from ..utils.cache_management import rmtree_safe
 
         logger.info(f"Installing git repo to {target_dir}: {self.url}@{self.ref}")
 
@@ -225,7 +225,7 @@ async def install_to(self, target_dir: Path) -> None:
             # Clean up partial install
             if target_dir.exists():
                 logger.debug(f"Cleaning up partial install at {target_dir}")
-                shutil.rmtree(target_dir)
+                rmtree_safe(target_dir)
             raise InstallError(
                 f"Failed to install {self.url}@{self.ref} to {target_dir}: {e}"
             )

amplifier_app_cli/utils/cache_management.py

@@ -13,12 +13,37 @@
 from __future__ import annotations
 
 import logging
+import os
 import shutil
+import stat
+import sys
 from pathlib import Path
 
 logger = logging.getLogger(__name__)
 
 
+def rmtree_safe(path: Path) -> None:
+    """Remove a directory tree, handling read-only files on Windows.
+
+    Git pack files (.idx, .pack) are created read-only on Windows, causing
+    shutil.rmtree() to fail with [WinError 5] Access is denied. This wrapper
+    adds an error handler that strips the read-only bit before retrying.
+    """
+    if sys.platform != "win32":
+        shutil.rmtree(path)
+        return
+
+    def _handle_readonly(func: object, path: str, exc: BaseException) -> None:
+        os.chmod(path, stat.S_IWRITE)
+        if callable(func):
+            func(path)
+
+    if sys.version_info >= (3, 12):
+        shutil.rmtree(path, onexc=_handle_readonly)
+    else:
+        shutil.rmtree(path, onerror=_handle_readonly)  # type: ignore[call-arg]
+
+
 def get_amplifier_dir() -> Path:
     """Return the ~/.amplifier directory path."""
     return Path.home() / ".amplifier"
@@ -59,7 +84,7 @@ def clear_download_cache(dry_run: bool = False) -> tuple[int, bool]:
             return (count, True)
 
         # Remove entire cache directory
-        shutil.rmtree(cache_dir)
+        rmtree_safe(cache_dir)
         logger.debug(f"Cleared {count} items from cache")
 
         # Recreate empty cache directory

amplifier_app_cli/utils/module_cache.py

@@ -16,11 +16,12 @@
 import json
 import logging
 import re
-import shutil
 from collections.abc import Callable
 from dataclasses import dataclass
 from pathlib import Path
 
+from .cache_management import rmtree_safe
+
 try:
     import tomllib
 except ImportError:
@@ -62,7 +63,10 @@ def get_bundle_name(cache_path: Path) -> str | None:
                     frontmatter = yaml.safe_load(parts[1])
                     if isinstance(frontmatter, dict):
                         bundle_section = frontmatter.get("bundle", {})
-                        if isinstance(bundle_section, dict) and "name" in bundle_section:
+                        if (
+                            isinstance(bundle_section, dict)
+                            and "name" in bundle_section
+                        ):
                             return bundle_section["name"]
         except Exception as e:
             logger.debug(f"Could not parse bundle.md frontmatter: {e}")
@@ -98,7 +102,9 @@ def get_module_info_from_pyproject(cache_path: Path) -> tuple[str | None, str |
 
     try:
         data = tomllib.loads(pyproject.read_text(encoding="utf-8"))
-        entry_points = data.get("project", {}).get("entry-points", {}).get("amplifier.modules", {})
+        entry_points = (
+            data.get("project", {}).get("entry-points", {}).get("amplifier.modules", {})
+        )
 
         if not entry_points:
             return None, None
@@ -146,7 +152,9 @@ class CachedModuleInfo:
     distinguishes between them (module_type="bundle" for bundles).
     """
 
-    module_id: str  # Entry point key for modules (e.g., "tool-bash"), bundle name for bundles
+    module_id: (
+        str  # Entry point key for modules (e.g., "tool-bash"), bundle name for bundles
+    )
     module_type: str  # tool, hook, provider, orchestrator, context, agent, bundle
     ref: str
     sha: str
@@ -408,7 +416,7 @@ def clear_module_cache(
                 try:
                     if progress_callback:
                         progress_callback(entry.name, "clearing")
-                    shutil.rmtree(entry)
+                    rmtree_safe(entry)
                     cleared += 1
                 except Exception as e:
                     logger.warning(f"Could not clear {entry}: {e}")
@@ -435,7 +443,7 @@ def clear_module_cache(
         # Delete cache directory
         try:
             if module.cache_path.exists():
-                shutil.rmtree(module.cache_path)
+                rmtree_safe(module.cache_path)
                 cleared += 1
                 logger.debug(f"Cleared cache for {module.module_id}@{module.ref}")
         except Exception as e:
@@ -470,7 +478,7 @@ async def update_module(
     # pyproject.toml entry points (e.g., "provider-anthropic" not
     # "amplifier-module-provider-anthropic")
     if repo_name.startswith("amplifier-module-"):
-        module_id = repo_name[len("amplifier-module-"):]
+        module_id = repo_name[len("amplifier-module-") :]
     else:
         module_id = repo_name