[fixup] Fix leaked temporary pip $HOME on exit

Fixup "711d8710"

src/zc/buildout/easy_install.py

@@ -18,7 +18,6 @@ It doesn't install scripts.  It uses setuptools and requires it to be
 installed.
 """
 
-import atexit
 import copy
 import distutils.errors
 import distutils.sysconfig
@@ -1843,67 +1842,73 @@ try:
 except ImportError:
     PIP_HAS_PYTHON_VERSION_WARNING_OPTION = False
 
-# Temporary HOME with .pydistutils.cfg to disable setup_requires
-pip_pydistutils_home = tempfile.mkdtemp('pip-pydistutils-home')
-with open(os.path.join(pip_pydistutils_home, '.pydistutils.cfg'), 'w') as f:
-    f.write("[easy_install]\n"
-            "index-url = file:///dev/null")
-atexit.register(zc.buildout.rmtree.rmtree, pip_pydistutils_home)
 
 def call_pip_command(command, operand, options, verbosity=-10):
     """
     Call `pip <command...> <operand...>` from a subprocess
     with appropriate options and environment.
     """
-    env = os.environ.copy()
-    pythonpath = pip_path[:]
-    pythonpath.extend(env.get(k) for k in ('PYTHONPATH', 'PYTHONEXTRAPATH'))
-    env['PYTHONPATH'] = os.pathsep.join(p for p in pythonpath if p)
-
-    args = [sys.executable, '-m', 'pip']
-    args.extend(command)
-    args.append('--no-deps')
-
-    log_level = logger.getEffectiveLevel()
-    pip_level = log_level - verbosity
-    if pip_level >= logging.WARNING:
-        args.append('-' + 'q' * (1 + (pip_level >= logging.ERROR))) # -q or -qq
-    elif pip_level < logging.INFO:
-        args.append('-' + 'v' * (1 + (pip_level < logging.DEBUG))) # -v or -vv
-    # Note: more recent pip accepts even -vvv and -qqq.
-
-    if not options._allow_picked_versions:
-        # Prevent pip from installing build dependencies on the fly
-        # without respecting pinned versions. This only works for
-        # PEP 517 specifications using pyproject.toml and not for
-        # dependencies in setup_requires option in legacy setup.py
-        args.append('--no-index')
-        args.append('--no-build-isolation')
-
-        # Prevent setuptools from downloading and thus installing
-        # build dependencies specified in setup_requires option of
-        # legacy setup.py by providing a crafted .pydistutils.cfg.
-        # This is used in complement to --no-build-isolation.
-        env['HOME'] = pip_pydistutils_home
-
-    if PIP_HAS_PYTHON_VERSION_WARNING_OPTION:
-        # Let pip display Python warnings only on first run.
-        if not hasattr(call_pip_command, 'displayed'):
-            call_pip_command.displayed = True
-        else:
-            args.append('--no-python-version-warning')
+    cleanup = []
+    try:
+        env = os.environ.copy()
+        pythonpath = pip_path[:]
+        pythonpath.extend(
+            env.get(k) for k in ('PYTHONPATH', 'PYTHONEXTRAPATH'))
+        env['PYTHONPATH'] = os.pathsep.join(p for p in pythonpath if p)
+
+        args = [sys.executable, '-m', 'pip']
+        args.extend(command)
+        args.append('--no-deps')
+
+        log_level = logger.getEffectiveLevel()
+        pip_level = log_level - verbosity
+        if pip_level >= logging.WARNING:
+            args.append('-' + 'q' * (1 + (pip_level >= logging.ERROR)))
+        elif pip_level < logging.INFO:
+            args.append('-' + 'v' * (1 + (pip_level < logging.DEBUG)))
+        # Note: more recent pip accepts even -vvv and -qqq.
+
+        if not options._allow_picked_versions:
+            # Prevent pip from installing build dependencies on the fly
+            # without respecting pinned versions. This only works for
+            # PEP 517 specifications using pyproject.toml and not for
+            # dependencies in setup_requires option in legacy setup.py
+            args.append('--no-index')
+            args.append('--no-build-isolation')
+
+            # Prevent setuptools from downloading and thus installing
+            # build dependencies specified in setup_requires option of
+            # legacy setup.py by providing a crafted .pydistutils.cfg.
+            # This is used in complement to --no-build-isolation.
+            pip_home = tempfile.mkdtemp('pip-pydistutils-home')
+            cleanup.append(lambda: zc.buildout.rmtree.rmtree(pip_home))
+            with open(os.path.join(pip_home, '.pydistutils.cfg'), 'w') as f:
+                f.write("[easy_install]\n"
+                        "index_url = file:///dev/null")
+            env['HOME'] = pip_home
+
+        if PIP_HAS_PYTHON_VERSION_WARNING_OPTION:
+            # Let pip display Python warnings only on first run.
+            if not hasattr(call_pip_command, 'displayed'):
+                call_pip_command.displayed = True
+            else:
+                args.append('--no-python-version-warning')
 
-    args.extend(operand)
+        args.extend(operand)
 
-    if log_level < logging.DEBUG:
-        # Log this only when buildout log level is quite low
-        logger.debug('Running pip %s', ' '.join(command[0:1] + operand))
-    if log_level < 0:
-        # Log this only when buildout log level is even lower
-        logger.debug('%s\nPYTHONPATH=%s\n', ' '.join(args), env['PYTHONPATH'])
+        if log_level < logging.DEBUG:
+            # Log this only when buildout log level is quite low
+            logger.debug('Running pip %s', ' '.join(command[0:1] + operand))
+        if log_level < 0:
+            # Log this only when buildout log level is even lower
+            logger.debug(
+                '%s\nPYTHONPATH=%s\n', ' '.join(args), env['PYTHONPATH'])
 
-    sys.stdout.flush() # We want any pending output first
-    subprocess.check_call(args, env=env)
+        sys.stdout.flush() # We want any pending output first
+        subprocess.check_call(args, env=env)
+    finally:
+        for f in cleanup:
+            f()
 
 
 def call_pip_editable(path, dest, options, verbosity=-10):