Use a special technique to remove git repos on Windows

CHANGELOG.md

@@ -1,5 +1,11 @@
 ## Unreleased
 
+### Bugfixes
+
+#### Removing a git repo on Windows fails
+
+One needs to remove the "read only" flags on certain files in the git repo in order to remove it.
+
 ## 2.0.0
 
 ### Moving more code to Python

bench_runner/git.py

@@ -5,7 +5,6 @@
 import contextlib
 import datetime
 from pathlib import Path
-import shutil
 import subprocess
 import re
 
@@ -14,6 +13,7 @@
 
 
 from .util import PathLike
+from . import util
 
 
 def get_log(
@@ -147,7 +147,7 @@ def clone(
         if is_hash and (dirname / ".git").is_dir() and get_git_hash(dirname) == branch:
             # This is a git repo, and the hash matches
             return
-        shutil.rmtree(dirname)
+        util.smart_rmtree(dirname)
 
     # Fetching a hash and fetching a branch require different approaches
 

bench_runner/util.py

@@ -5,6 +5,7 @@
 from pathlib import Path
 import shutil
 import subprocess
+import stat
 import sys
 from typing import Iterable, Iterator, Literal, TypeAlias, Union
 
@@ -105,6 +106,37 @@ def valid_version(version: str) -> bool:
         return False
 
 
+if sys.platform.startswith("win"):
+    if sys.version_info >= (3, 12):
+
+        def smart_rmtree(path: PathLike) -> None:
+            def onexc(func, path, exc):
+                # Is the error an access error?
+                if not os.access(path, os.W_OK):
+                    os.chmod(path, stat.S_IWUSR)
+                    func(path)
+                else:
+                    raise exc
+
+            shutil.rmtree(path, onexc=onexc)
+
+    else:
+
+        def smart_rmtree(path: PathLike) -> None:
+            def onerror(func, path, exc_info):
+                # Is the error an access error?
+                if not os.access(path, os.W_OK):
+                    os.chmod(path, stat.S_IWUSR)
+                    func(path)
+                else:
+                    raise exc_info[1]
+
+            shutil.rmtree(path, onerror=onerror)
+
+else:
+    smart_rmtree = shutil.rmtree
+
+
 if os.getenv("GITHUB_ACTIONS") == "true":
 
     @contextlib.contextmanager