diff --git a/depot_tools/win_toolchain/package_from_installed.py b/depot_tools/win_toolchain/package_from_installed.py
new file mode 100644
index 00000000..fc336371
--- /dev/null
+++ b/depot_tools/win_toolchain/package_from_installed.py
@@ -0,0 +1,582 @@
+#!/usr/bin/env python3
+# Copyright 2022 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+From a system-installed copy of the toolchain, packages all the required bits
+into a .zip file.
+
+It assumes default install locations for tools, on the C: drive.
+
+1. Start from a fresh Windows VM image.
+2. Download the VS installer. Run the installer with these parameters:
+    --add Microsoft.VisualStudio.Workload.NativeDesktop
+    --add Microsoft.VisualStudio.Component.VC.ATLMFC
+    --add Microsoft.VisualStudio.Component.VC.Tools.ARM64
+    --add Microsoft.VisualStudio.Component.VC.MFC.ARM64
+    --includeRecommended --passive
+These are equivalent to selecting the Desktop development with C++ workload,
+within that the Visual C++ MFC for x86 and x64 component, and then  Individual
+Components-> Compilers, build tools, and runtimes-> Visual C++ compilers and
+libraries for ARM64, and Individual Components-> SDKs, libraries, and
+frameworks-> Visual C++ MFC for ARM64 (which also brings in ATL for ARM64).
+3. Use Add or Remove Programs to find the Windows SDK installed with VS
+and modify it to include the debuggers.
+4. Run this script, which will build a <sha1>.zip, something like this:
+  python package_from_installed.py 2019|2022 -w 10.0.20348.0|<SDK version>
+
+Express is not yet supported by this script, but patches welcome (it's not too
+useful as the resulting zip can't be redistributed, and most will presumably
+have a Pro license anyway).
+"""
+
+from __future__ import print_function
+
+import collections
+import glob
+import json
+import optparse
+import os
+import platform
+import shutil
+import subprocess
+import sys
+import tempfile
+import zipfile
+
+import get_toolchain_if_necessary
+
+
+_vs_version = None
+_win_version = None
+_vc_tools = None
+SUPPORTED_VS_VERSIONS = ['2019', '2022']
+_allow_multiple_vs_installs = False
+
+
+def GetVSPath():
+  # Use vswhere to find the VS installation. This will find prerelease
+  # versions because -prerelease is specified. This assumes that only one
+  # version is installed.
+  command = (r'C:\Program Files (x86)\Microsoft Visual Studio\Installer'
+             r'\vswhere.exe -prerelease')
+  vs_version_marker = 'catalog_productLineVersion: '
+  vs_path_marker = 'installationPath: '
+  output = subprocess.check_output(command, universal_newlines=True)
+  vs_path = None
+  vs_installs_count = 0
+  matching_vs_path = ""
+  for line in output.splitlines():
+    if line.startswith(vs_path_marker):
+      # The path information comes first
+      vs_path = line[len(vs_path_marker):]
+      vs_installs_count += 1
+    if line.startswith(vs_version_marker):
+      # The version for that path comes later
+      if line[len(vs_version_marker):] == _vs_version:
+        matching_vs_path = vs_path
+
+  if vs_installs_count == 0:
+    raise Exception('VS %s path not found in vswhere output' % (_vs_version))
+  if vs_installs_count > 1:
+    if not _allow_multiple_vs_installs:
+      raise Exception('Multiple VS installs detected. This is unsupported. '
+                      'It is recommended that packaging be done on a clean VM '
+                      'with just one version installed. To proceed anyway add '
+                      'the --allow_multiple_vs_installs flag to this script')
+    else:
+      print('Multiple VS installs were detected. This is unsupported. '
+            'Proceeding anyway')
+  return matching_vs_path
+
+
+def ExpandWildcards(root, sub_dir):
+  # normpath is needed to change '/' to '\\' characters.
+  path = os.path.normpath(os.path.join(root, sub_dir))
+  matches = glob.glob(path)
+  if len(matches) != 1:
+    raise Exception('%s had %d matches - should be one' % (path, len(matches)))
+  return matches[0]
+
+
+def BuildRepackageFileList(src_dir):
+  # Strip off a trailing separator if present
+  if src_dir.endswith(os.path.sep):
+    src_dir = src_dir[:-len(os.path.sep)]
+
+  # Ensure .\Windows Kits\10\Debuggers exists and fail to repackage if it
+  # doesn't.
+  debuggers_path = os.path.join(src_dir, 'Windows Kits', '10', 'Debuggers')
+  if not os.path.exists(debuggers_path):
+    raise Exception('Repacking failed. Missing %s.' % (debuggers_path))
+
+  result = []
+  for root, _, files in os.walk(src_dir):
+    for f in files:
+      final_from = os.path.normpath(os.path.join(root, f))
+      dest = final_from[len(src_dir) + 1:]
+      result.append((final_from, dest))
+  return result
+
+
+def BuildFileList(override_dir, include_arm, vs_path):
+  result = []
+
+  # Subset of VS corresponding roughly to VC.
+  paths = [
+      'DIA SDK/bin',
+      'DIA SDK/idl',
+      'DIA SDK/include',
+      'DIA SDK/lib',
+      _vc_tools + '/atlmfc',
+      _vc_tools + '/crt',
+      'VC/redist',
+  ]
+
+  if override_dir:
+    paths += [
+        (os.path.join(override_dir, 'bin'), _vc_tools + '/bin'),
+        (os.path.join(override_dir, 'include'), _vc_tools + '/include'),
+        (os.path.join(override_dir, 'lib'), _vc_tools + '/lib'),
+    ]
+  else:
+    paths += [
+        _vc_tools + '/bin',
+        _vc_tools + '/include',
+        _vc_tools + '/lib',
+    ]
+
+  paths += [
+      ('VC/redist/MSVC/14.*.*/x86/Microsoft.VC*.CRT', 'sys32'),
+      ('VC/redist/MSVC/14.*.*/x86/Microsoft.VC*.CRT',
+       'Windows Kits/10//bin/x86'),
+      ('VC/redist/MSVC/14.*.*/debug_nonredist/x86/Microsoft.VC*.DebugCRT',
+       'sys32'),
+      ('VC/redist/MSVC/14.*.*/x64/Microsoft.VC*.CRT', 'sys64'),
+      ('VC/redist/MSVC/14.*.*/x64/Microsoft.VC*.CRT', 'VC/bin/amd64_x86'),
+      ('VC/redist/MSVC/14.*.*/x64/Microsoft.VC*.CRT', 'VC/bin/amd64'),
+      ('VC/redist/MSVC/14.*.*/x64/Microsoft.VC*.CRT',
+       'Windows Kits/10/bin/x64'),
+      ('VC/redist/MSVC/14.*.*/debug_nonredist/x64/Microsoft.VC*.DebugCRT',
+       'sys64'),
+  ]
+  if include_arm:
+    paths += [
+        ('VC/redist/MSVC/14.*.*/arm64/Microsoft.VC*.CRT', 'sysarm64'),
+        ('VC/redist/MSVC/14.*.*/arm64/Microsoft.VC*.CRT', 'VC/bin/amd64_arm64'),
+        ('VC/redist/MSVC/14.*.*/arm64/Microsoft.VC*.CRT', 'VC/bin/arm64'),
+        ('VC/redist/MSVC/14.*.*/arm64/Microsoft.VC*.CRT',
+         'Windows Kits/10/bin/arm64'),
+        ('VC/redist/MSVC/14.*.*/debug_nonredist/arm64/Microsoft.VC*.DebugCRT',
+         'sysarm64'),
+    ]
+
+  for path in paths:
+    src = path[0] if isinstance(path, tuple) else path
+    # Note that vs_path is ignored if src is an absolute path.
+    combined = ExpandWildcards(vs_path, src)
+    if not os.path.exists(combined):
+      raise Exception('%s missing.' % combined)
+    if not os.path.isdir(combined):
+      raise Exception('%s not a directory.' % combined)
+    for root, _, files in os.walk(combined):
+      for f in files:
+        # vctip.exe doesn't shutdown, leaving locks on directories. It's
+        # optional so let's avoid this problem by not packaging it.
+        # https://crbug.com/735226
+        if f.lower() =='vctip.exe':
+          continue
+        final_from = os.path.normpath(os.path.join(root, f))
+        if isinstance(path, tuple):
+          assert final_from.startswith(combined)
+          dest = final_from[len(combined) + 1:]
+          result.append(
+              (final_from, os.path.normpath(os.path.join(path[1], dest))))
+        else:
+          assert final_from.startswith(vs_path)
+          dest = final_from[len(vs_path) + 1:]
+          result.append((final_from, dest))
+
+  command = (r'reg query "HKLM\SOFTWARE\Microsoft\Windows Kits\Installed Roots"'
+             r' /v KitsRoot10')
+  marker = "    KitsRoot10    REG_SZ    "
+  sdk_path = None
+  output = subprocess.check_output(command, universal_newlines=True)
+  for line in output.splitlines():
+    if line.startswith(marker):
+      sdk_path = line[len(marker):]
+
+  # Strip off a trailing slash if present
+  if sdk_path.endswith(os.path.sep):
+    sdk_path = sdk_path[:-len(os.path.sep)]
+
+  debuggers_path = os.path.join(sdk_path, 'Debuggers')
+  if not os.path.exists(debuggers_path):
+    raise Exception('Packaging failed. Missing %s.' % (debuggers_path))
+
+  for root, _, files in os.walk(sdk_path):
+    for f in files:
+      combined = os.path.normpath(os.path.join(root, f))
+      # Some of the files in this directory are exceedingly long (and exceed
+      # _MAX_PATH for any moderately long root), so exclude them. We don't need
+      # them anyway. Exclude/filter/skip others just to save space.
+      tail = combined[len(sdk_path) + 1:]
+      skip_dir = False
+      for dir in ['References\\', 'Windows Performance Toolkit\\', 'Testing\\',
+                  'App Certification Kit\\', 'Extension SDKs\\',
+                  'Assessment and Deployment Kit\\']:
+        if tail.startswith(dir):
+          skip_dir = True
+      if skip_dir:
+        continue
+      # There may be many Include\Lib\Source\bin directories for many different
+      # versions of Windows and packaging them all wastes ~450 MB
+      # (uncompressed) per version and wastes time. Only copy the specified
+      # version. Note that the SDK version number started being part of the bin
+      # path with 10.0.20348.0.
+      if (tail.startswith('Include\\') or tail.startswith('Lib\\') or
+          tail.startswith('Source\\') or tail.startswith('bin\\')):
+        if tail.count(_win_version) == 0:
+          continue
+      to = os.path.join('Windows Kits', '10', tail)
+      result.append((combined, to))
+
+  # Copy the x86 ucrt DLLs to all directories with x86 binaries that are
+  # added to the path by SetEnv.cmd, and to sys32. Starting with the 17763
+  # SDK the ucrt files are in _win_version\ucrt instead of just ucrt.
+  ucrt_dir = os.path.join(sdk_path, 'redist', _win_version, r'ucrt\dlls\x86')
+  if not os.path.exists(ucrt_dir):
+    ucrt_dir = os.path.join(sdk_path, r'redist\ucrt\dlls\x86')
+  ucrt_paths = glob.glob(ucrt_dir + r'\*')
+  assert(len(ucrt_paths) > 0)
+  for ucrt_path in ucrt_paths:
+    ucrt_file = os.path.split(ucrt_path)[1]
+    for dest_dir in [ r'Windows Kits\10\bin\x86', 'sys32' ]:
+      result.append((ucrt_path, os.path.join(dest_dir, ucrt_file)))
+
+  # Copy the x64 ucrt DLLs to all directories with x64 binaries that are
+  # added to the path by SetEnv.cmd, and to sys64.
+  ucrt_dir = os.path.join(sdk_path, 'redist', _win_version, r'ucrt\dlls\x64')
+  if not os.path.exists(ucrt_dir):
+    ucrt_dir = os.path.join(sdk_path, r'redist\ucrt\dlls\x64')
+  ucrt_paths = glob.glob(ucrt_dir + r'\*')
+  assert(len(ucrt_paths) > 0)
+  for ucrt_path in ucrt_paths:
+    ucrt_file = os.path.split(ucrt_path)[1]
+    for dest_dir in [ r'VC\bin\amd64_x86', r'VC\bin\amd64',
+                      r'Windows Kits\10\bin\x64', 'sys64']:
+      result.append((ucrt_path, os.path.join(dest_dir, ucrt_file)))
+
+  system_crt_files = [
+      # Needed to let debug binaries run.
+      'ucrtbased.dll',
+  ]
+  cpu_pairs = [
+    ('x86', 'sys32'),
+    ('x64', 'sys64'),
+  ]
+  if include_arm:
+    cpu_pairs += [
+      ('arm64', 'sysarm64'),
+    ]
+  for system_crt_file in system_crt_files:
+    for cpu_pair in cpu_pairs:
+      target_cpu, dest_dir = cpu_pair
+      src_path = os.path.join(sdk_path, 'bin', _win_version, target_cpu, 'ucrt')
+      result.append((os.path.join(src_path, system_crt_file),
+                     os.path.join(dest_dir, system_crt_file)))
+
+  # Generically drop all arm stuff that we don't need, and
+  # drop .msi files because we don't need installers and drop
+  # samples since those are not used by any tools.
+  def is_skippable(f):
+    return ('arm\\' in f.lower() or
+            (not include_arm and 'arm64\\' in f.lower()) or
+            'samples\\' in f.lower() or
+            f.lower().endswith(('.msi',
+                                '.msm')))
+  return [(f, t) for f, t in result if not is_skippable(f)]
+
+def GenerateSetEnvCmd(target_dir):
+  """Generate a batch file that gyp expects to exist to set up the compiler
+  environment.
+
+  This is normally generated by a full install of the SDK, but we
+  do it here manually since we do not do a full install."""
+  vc_tools_parts = _vc_tools.split('/')
+
+  # All these paths are relative to the root of the toolchain package.
+  include_dirs = [
+    ['Windows Kits', '10', 'Include', _win_version, 'um'],
+    ['Windows Kits', '10', 'Include', _win_version, 'shared'],
+    ['Windows Kits', '10', 'Include', _win_version, 'winrt'],
+  ]
+  include_dirs.append(['Windows Kits', '10', 'Include', _win_version, 'ucrt'])
+  include_dirs.extend([
+    vc_tools_parts + ['include'],
+    vc_tools_parts + ['atlmfc', 'include'],
+  ])
+  libpath_dirs = [
+    vc_tools_parts + ['lib', 'x86', 'store', 'references'],
+    ['Windows Kits', '10', 'UnionMetadata', _win_version],
+  ]
+  # Common to x86, x64, and arm64
+  env = collections.OrderedDict([
+    # Yuck: These have a trailing \ character. No good way to represent this in
+    # an OS-independent way.
+    ('VSINSTALLDIR', [['.\\']]),
+    ('VCINSTALLDIR', [['VC\\']]),
+    ('INCLUDE', include_dirs),
+    ('LIBPATH', libpath_dirs),
+  ])
+  # x86. Always use amd64_x86 cross, not x86 on x86.
+  env['VCToolsInstallDir'] = [vc_tools_parts[:]]
+  # Yuck: This one ends in a path separator as well.
+  env['VCToolsInstallDir'][0][-1] += os.path.sep
+  env_x86 = collections.OrderedDict([
+      (
+          'PATH',
+          [
+              ['Windows Kits', '10', 'bin', _win_version, 'x64'],
+              vc_tools_parts + ['bin', 'HostX64', 'x86'],
+              vc_tools_parts + ['bin', 'HostX64', 'x64'
+                                              ],  # Needed for mspdb1x0.dll.
+          ]),
+      ('LIB', [
+          vc_tools_parts + ['lib', 'x86'],
+          ['Windows Kits', '10', 'Lib', _win_version, 'um', 'x86'],
+          ['Windows Kits', '10', 'Lib', _win_version, 'ucrt', 'x86'],
+          vc_tools_parts + ['atlmfc', 'lib', 'x86'],
+      ]),
+  ])
+
+  # x64.
+  env_x64 = collections.OrderedDict([
+      ('PATH', [
+          ['Windows Kits', '10', 'bin', _win_version, 'x64'],
+          vc_tools_parts + ['bin', 'HostX64', 'x64'],
+      ]),
+      ('LIB', [
+          vc_tools_parts + ['lib', 'x64'],
+          ['Windows Kits', '10', 'Lib', _win_version, 'um', 'x64'],
+          ['Windows Kits', '10', 'Lib', _win_version, 'ucrt', 'x64'],
+          vc_tools_parts + ['atlmfc', 'lib', 'x64'],
+      ]),
+  ])
+
+  # arm64.
+  env_arm64 = collections.OrderedDict([
+      ('PATH', [
+          ['Windows Kits', '10', 'bin', _win_version, 'x64'],
+          vc_tools_parts + ['bin', 'HostX64', 'arm64'],
+          vc_tools_parts + ['bin', 'HostX64', 'x64'],
+      ]),
+      ('LIB', [
+          vc_tools_parts + ['lib', 'arm64'],
+          ['Windows Kits', '10', 'Lib', _win_version, 'um', 'arm64'],
+          ['Windows Kits', '10', 'Lib', _win_version, 'ucrt', 'arm64'],
+          vc_tools_parts + ['atlmfc', 'lib', 'arm64'],
+      ]),
+  ])
+
+  def BatDirs(dirs):
+    return ';'.join(['%cd%\\' + os.path.join(*d) for d in dirs])
+  set_env_prefix = os.path.join(target_dir, r'Windows Kits\10\bin\SetEnv')
+  with open(set_env_prefix + '.cmd', 'w') as f:
+    # The prologue changes the current directory to the root of the toolchain
+    # package, so that path entries can be set up without needing ..\..\..\
+    # components.
+    f.write('@echo off\n'
+            ':: Generated by win_toolchain\\package_from_installed.py.\n'
+            'pushd %~dp0..\..\..\n')
+    for var, dirs in env.items():
+      f.write('set %s=%s\n' % (var, BatDirs(dirs)))
+    f.write('if "%1"=="/x64" goto x64\n')
+    f.write('if "%1"=="/arm64" goto arm64\n')
+
+    for var, dirs in env_x86.items():
+      f.write('set %s=%s%s\n' % (
+          var, BatDirs(dirs), ';%PATH%' if var == 'PATH' else ''))
+    f.write('goto :END\n')
+
+    f.write(':x64\n')
+    for var, dirs in env_x64.items():
+      f.write('set %s=%s%s\n' % (
+          var, BatDirs(dirs), ';%PATH%' if var == 'PATH' else ''))
+    f.write('goto :END\n')
+
+    f.write(':arm64\n')
+    for var, dirs in env_arm64.items():
+      f.write('set %s=%s%s\n' % (
+          var, BatDirs(dirs), ';%PATH%' if var == 'PATH' else ''))
+    f.write('goto :END\n')
+    f.write(':END\n')
+    # Restore the original directory.
+    f.write('popd\n')
+  with open(set_env_prefix + '.x86.json', 'wt', newline='') as f:
+    assert not set(env.keys()) & set(env_x86.keys()), 'dupe keys'
+    json.dump({'env': collections.OrderedDict(list(env.items()) + list(env_x86.items()))},
+              f)
+  with open(set_env_prefix + '.x64.json', 'wt', newline='') as f:
+    assert not set(env.keys()) & set(env_x64.keys()), 'dupe keys'
+    json.dump({'env': collections.OrderedDict(list(env.items()) + list(env_x64.items()))},
+              f)
+  with open(set_env_prefix + '.arm64.json', 'wt', newline='') as f:
+    assert not set(env.keys()) & set(env_arm64.keys()), 'dupe keys'
+    json.dump({'env': collections.OrderedDict(list(env.items()) + list(env_arm64.items()))},
+              f)
+
+
+def AddEnvSetup(files, include_arm):
+  """We need to generate this file in the same way that the "from pieces"
+  script does, so pull that in here."""
+  tempdir = tempfile.mkdtemp()
+  os.makedirs(os.path.join(tempdir, 'Windows Kits', '10', 'bin'))
+  GenerateSetEnvCmd(tempdir)
+  files.append((
+      os.path.join(tempdir, 'Windows Kits', '10', 'bin', 'SetEnv.cmd'),
+      'Windows Kits\\10\\bin\\SetEnv.cmd'))
+  files.append((
+      os.path.join(tempdir, 'Windows Kits', '10', 'bin', 'SetEnv.x86.json'),
+      'Windows Kits\\10\\bin\\SetEnv.x86.json'))
+  files.append((
+      os.path.join(tempdir, 'Windows Kits', '10', 'bin', 'SetEnv.x64.json'),
+      'Windows Kits\\10\\bin\\SetEnv.x64.json'))
+  if include_arm:
+    files.append((
+        os.path.join(tempdir, 'Windows Kits', '10', 'bin', 'SetEnv.arm64.json'),
+        'Windows Kits\\10\\bin\\SetEnv.arm64.json'))
+  vs_version_file = os.path.join(tempdir, 'VS_VERSION')
+  with open(vs_version_file, 'wt', newline='') as version:
+    print(_vs_version, file=version)
+  files.append((vs_version_file, 'VS_VERSION'))
+
+
+def RenameToSha1(output):
+  """Determine the hash in the same way that the unzipper does to rename the
+  # .zip file."""
+  print('Extracting to determine hash...')
+  tempdir = tempfile.mkdtemp()
+  old_dir = os.getcwd()
+  os.chdir(tempdir)
+  rel_dir = 'vs_files'
+  with zipfile.ZipFile(
+      os.path.join(old_dir, output), 'r', zipfile.ZIP_DEFLATED, True) as zf:
+    zf.extractall(rel_dir)
+  print('Hashing...')
+  sha1 = get_toolchain_if_necessary.CalculateHash(rel_dir, None)
+  # Shorten from forty characters to ten. This is still enough to avoid
+  # collisions, while being less unwieldy and reducing the risk of MAX_PATH
+  # failures.
+  sha1 = sha1[:10]
+  os.chdir(old_dir)
+  shutil.rmtree(tempdir)
+  final_name = sha1 + '.zip'
+  os.rename(output, final_name)
+  print('Renamed %s to %s.' % (output, final_name))
+
+
+def main():
+  if sys.version_info[0] < 3:
+    print('This script requires Python 3')
+    sys.exit(10)
+  usage = 'usage: %prog [options] 2019|2022'
+  parser = optparse.OptionParser(usage)
+  parser.add_option('-w', '--winver', action='store', type='string',
+                    dest='winver', default='10.0.20348.0',
+                    help='Windows SDK version, such as 10.0.20348.0')
+  parser.add_option('-d', '--dryrun', action='store_true', dest='dryrun',
+                    default=False,
+                    help='scan for file existence and prints statistics')
+  parser.add_option('--noarm', action='store_false', dest='arm',
+                    default=True,
+                    help='Avoids arm parts of the SDK')
+  parser.add_option('--override', action='store', type='string',
+                    dest='override_dir', default=None,
+                    help='Specify alternate bin/include/lib directory')
+  parser.add_option('--repackage', action='store', type='string',
+                    dest='repackage_dir', default=None,
+                    help='Specify raw directory to be packaged, for hot fixes.')
+  parser.add_option('--allow_multiple_vs_installs', action='store_true',
+                    default=False, dest='allow_multiple_vs_installs',
+                    help='Specify if multiple VS installs are allowed.')
+  (options, args) = parser.parse_args()
+
+  if options.repackage_dir:
+    files = BuildRepackageFileList(options.repackage_dir)
+  else:
+    if len(args) != 1 or args[0] not in SUPPORTED_VS_VERSIONS:
+      print('Must specify 2019 or 2022')
+      parser.print_help();
+      return 1
+
+    if options.override_dir:
+      if (not os.path.exists(os.path.join(options.override_dir, 'bin')) or
+          not os.path.exists(os.path.join(options.override_dir, 'include')) or
+          not os.path.exists(os.path.join(options.override_dir, 'lib'))):
+        print('Invalid override directory - must contain bin/include/lib dirs')
+        return 1
+
+    global _vs_version
+    _vs_version = args[0]
+    global _win_version
+    _win_version = options.winver
+    global _vc_tools
+    global _allow_multiple_vs_installs
+    _allow_multiple_vs_installs = options.allow_multiple_vs_installs
+    vs_path = GetVSPath()
+    temp_tools_path = ExpandWildcards(vs_path, 'VC/Tools/MSVC/14.*.*')
+    # Strip off the leading vs_path characters and switch back to / separators.
+    _vc_tools = temp_tools_path[len(vs_path) + 1:].replace('\\', '/')
+
+    print('Building file list for VS %s Windows %s...' % (_vs_version, _win_version))
+    files = BuildFileList(options.override_dir, options.arm, vs_path)
+
+    AddEnvSetup(files, options.arm)
+
+  if False:
+    for f in files:
+      print(f[0], '->', f[1])
+    return 0
+
+  output = 'out.zip'
+  if os.path.exists(output):
+    os.unlink(output)
+  count = 0
+  version_match_count = 0
+  total_size = 0
+  missing_files = False
+  with zipfile.ZipFile(output, 'w', zipfile.ZIP_DEFLATED, True) as zf:
+    for disk_name, archive_name in files:
+      sys.stdout.write('\r%d/%d ...%s' % (count, len(files), disk_name[-40:]))
+      sys.stdout.flush()
+      count += 1
+      if not options.repackage_dir and disk_name.count(_win_version) > 0:
+        version_match_count += 1
+      if os.path.exists(disk_name):
+        total_size += os.path.getsize(disk_name)
+        if not options.dryrun:
+          zf.write(disk_name, archive_name)
+      else:
+        missing_files = True
+        sys.stdout.write('\r%s does not exist.\n\n' % disk_name)
+        sys.stdout.flush()
+  sys.stdout.write('\r%1.3f GB of data in %d files, %d files for %s.%s\n' %
+      (total_size / 1e9, count, version_match_count, _win_version, ' '*50))
+  if options.dryrun:
+    return 0
+  if missing_files:
+    raise Exception('One or more files were missing - aborting')
+  if not options.repackage_dir and version_match_count == 0:
+    raise Exception('No files found that match the specified winversion')
+  sys.stdout.write('\rWrote to %s.%s\n' % (output, ' '*50))
+  sys.stdout.flush()
+
+  RenameToSha1(output)
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())