Exclude .venv from Time Machine backups

poetry/utils/env.py

@@ -4,6 +4,7 @@
 import json
 import os
 import platform
+import plistlib
 import re
 import shutil
 import subprocess
@@ -1002,7 +1003,19 @@ def build_venv(
 
         args.append(str(path))
 
-        return virtualenv.cli_run(args)
+        cli_result = virtualenv.cli_run(args)
+
+        # Exclude the venv folder from from macOS Time Machine backups
+        if sys.platform == "darwin":
+            import xattr
+
+            xattr.setxattr(
+                str(path),
+                "com.apple.metadata:com_apple_backup_excludeItem",
+                plistlib.dumps("com.apple.backupd", fmt=plistlib.FMT_BINARY),
+            )
+
+        return cli_result
 
     @classmethod
     def remove_venv(cls, path: Union[Path, str]) -> None:

pyproject.toml

@@ -50,6 +50,7 @@ keyring = ">=21.2.0"
 entrypoints = "^0.3"
 importlib-metadata = {version = "^1.6.0", python = "<3.8"}
 dataclasses = {version = "^0.8", python = "~3.6"}
+xattr = {version = "^0.9.7", markers = "sys_platform == 'darwin'"}
 
 [tool.poetry.dev-dependencies]
 pytest = "^6.2"

tests/utils/test_env.py

@@ -9,6 +9,7 @@
 
 import pytest
 import tomlkit
+import xattr
 
 from cleo.io.null_io import NullIO
 
@@ -77,6 +78,20 @@ def test_virtualenvs_with_spaces_in_their_path_work_as_expected(tmp_dir, manager
     assert venv.run("python", "-V", shell=True).startswith("Python")
 
 
+@pytest.mark.skipif(sys.platform != "darwin", reason="requires darwin")
+def test_venv_backup_exclusion(tmp_dir, manager):
+    venv_path = Path(tmp_dir) / "Virtual Env"
+
+    manager.build_venv(str(venv_path))
+
+    assert (
+        xattr.getxattr(
+            str(venv_path), "com.apple.metadata:com_apple_backup_excludeItem"
+        )
+        == b"bplist00_\x10\x11com.apple.backupd\x08\x00\x00\x00\x00\x00\x00\x01\x01\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x1c"
+    )
+
+
 def test_env_commands_with_spaces_in_their_arg_work_as_expected(tmp_dir, manager):
     venv_path = Path(tmp_dir) / "Virtual Env"
     manager.build_venv(str(venv_path))