Use system-installed Python dependencies instead of bundled libraries.
Remove the third-party library path setup, bundled dependency checks,
and compatibility fallbacks from the gsutil entry point. Import crcmod
directly from the system installation.
Remove obsolete Python 2 handling and warnings specific to bundled
dependencies.
--- ../gsutil.py	2026-10-18 14:05:21.161954563 +0300
+++ ../gsutil.py	2026-10-18 14:07:20.870135893 +0300
@@ -36,13 +36,6 @@
     "\t2. If you are unsure how to manage Python versions, visit [https://cloud.google.com/storage/docs/gsutil_install#specifications] for detailed instructions.".format(ver.major, ver.minor)
   )
 
-# setup a string to load the correct httplib2
-if sys.version_info.major == 2:
-  submodule_pyvers = 'python2'
-else:
-  submodule_pyvers = 'python3'
-
-
 def OutputAndExit(message):
   sys.stderr.write('%s\n' % message)
   sys.exit(1)
@@ -72,84 +65,12 @@
   OutputAndExit('Unable to determine where gsutil is installed. Sorry, '
                 'cannot run correctly without this.\n')
 
-# The wrapper script adds all third_party libraries to the Python path, since
-# we don't assume any third party libraries are installed system-wide.
-THIRD_PARTY_DIR = os.path.join(GSUTIL_DIR, 'third_party')
-VENDORED_DIR = os.path.join(THIRD_PARTY_DIR, 'vendored')
-
 # Flag for whether or not an import wrapper is used to measure time taken for
 # individual imports.
 MEASURING_TIME_ACTIVE = False
 
-# Filter out "module was already imported" warnings that get printed after we
-# add our bundled version of modules to the Python path.
-warnings.filterwarnings('ignore',
-                        category=UserWarning,
-                        message=r'.* httplib2 was already imported from')
-warnings.filterwarnings('ignore',
-                        category=UserWarning,
-                        message=r'.* oauth2client was already imported from')
-
-# List of third-party libraries. The first element of the tuple is the name of
-# the directory under third_party and the second element is the subdirectory
-# that needs to be added to sys.path.
-THIRD_PARTY_LIBS = [
-    ('argcomplete', ''),  # For tab-completion (gcloud installs only).
-    ('mock', ''),
-    ('funcsigs', ''),  # mock dependency
-    ('google-reauth-python', ''),  # Package name: google_reauth
-    ('pyu2f', ''),  # google_reauth dependency
-    ('pyasn1', ''),  # oauth2client dependency
-    ('pyasn1-modules', ''),  # oauth2client dependency
-    ('rsa', ''),  # oauth2client dependency
-    ('apitools', ''),
-    ('gcs-oauth2-boto-plugin', ''),
-    ('fasteners', ''),  # oauth2client and apitools dependency
-    ('monotonic', ''),  # fasteners dependency
-    ('pyparsing', ''),  # httplib2 dependency
-    ('httplib2', submodule_pyvers),
-    ('retry-decorator', ''),
-    ('six', ''),  # Python 2 / 3 compatibility dependency
-    ('cachetools', 'src'),  # google auth dependency
-    ('urllib3', 'src'),  # requests dependency
-    ('charset_normalizer', ''),  # requests dependency
-    ('chardet', ''),  # requests dependency
-    ('certifi', ''),  # requests dependency
-    ('idna', ''),  # requests dependency
-    ('requests', 'src'),  # google auth dependency
-    ('google-auth-library-python', ''),
-    ('google-auth-library-python-httplib2', ''), #Package name: google-auth-httplib2
-]
-
-# The wrapper script adds all third_party libraries to the Python path, since
-# we don't assume any third party libraries are installed system-wide.
-#
-# Note that vendored libraries (e.g. Boto) are added to the Python path in
-# gslib/__init__.py, as they will always be present even when bypassing this
-# script and invoking gslib.__main__.py's main() method directly.
-THIRD_PARTY_DIR = os.path.join(GSUTIL_DIR, 'third_party')
-for libdir, subdir in THIRD_PARTY_LIBS:
-  if not os.path.isdir(os.path.join(THIRD_PARTY_DIR, libdir)):
-    OutputAndExit(
-        'There is no %s library under the gsutil third-party directory (%s).\n'
-        'The gsutil command cannot work properly when installed this way.\n'
-        'Please re-install gsutil per the installation instructions.' %
-        (libdir, THIRD_PARTY_DIR))
-  sys.path.insert(0, os.path.join(THIRD_PARTY_DIR, libdir, subdir))
-
-CRCMOD_PATH = os.path.join(THIRD_PARTY_DIR, 'crcmod', submodule_pyvers)
-CRCMOD_OSX_PATH = os.path.join(THIRD_PARTY_DIR, 'crcmod_osx')
-try:
-  # pylint: disable=g-import-not-at-top
-  import crcmod
-except ImportError:
-  # Note: the bundled crcmod module under THIRD_PARTY_DIR does not include its
-  # compiled C extension, but we still add it to sys.path because other parts of
-  # gsutil assume that at least the core crcmod module will be available.
-  local_crcmod_path = (CRCMOD_OSX_PATH if 'darwin' in str(sys.platform).lower()
-                       else CRCMOD_PATH)
-  sys.path.insert(0, local_crcmod_path)
-
+# Third-party dependencies are provided by system packages.
+import crcmod
 
 def RunMain():
   _fix_google_module()