Try again if rmtree raises OsError: Directory not empty (#123)

I get this error a lot when rmtree tries to remove the directory. I am
not sure why it happens, but let's just try again in this case.

Author: hoodmane

pyodide_build/common.py

@@ -9,6 +9,7 @@
 import subprocess
 import sys
 import textwrap
+import time
 import tomllib
 import warnings
 import zipfile
@@ -493,3 +494,21 @@ def download_and_unpack_archive(
             # https://github.com/python/cpython/issues/112760
             warnings.simplefilter("ignore")
             shutil.unpack_archive(str(f_path), path)
+
+
+def retrying_rmtree(d):
+    """Sometimes rmtree fails with OSError: Directory not empty
+
+    Try again a few times if this happens.
+    See: https://github.com/python/cpython/issues/128076
+    """
+    for _ in range(3):
+        try:
+            return shutil.rmtree(d)
+        except OSError as e:
+            if e.strerror == "Directory not empty":
+                # wait a bit and try again up to 3 tries
+                time.sleep(0.01)
+            else:
+                raise
+    raise RuntimeError(f"shutil.rmtree('{d}') failed with ENOTEMPTY three times")

pyodide_build/recipe/builder.py

@@ -37,6 +37,7 @@
     make_zip_archive,
     modify_wheel,
     retag_wheel,
+    retrying_rmtree,
 )
 from pyodide_build.logger import logger
 from pyodide_build.recipe.bash_runner import (
@@ -243,7 +244,7 @@ def _prepare_source(self) -> None:
 
         # clear the build directory
         if self.build_dir.resolve().is_dir():
-            shutil.rmtree(self.build_dir)
+            retrying_rmtree(self.build_dir)
 
         self.build_dir.mkdir(parents=True, exist_ok=True)