Build OWT for iOS failed

[Guan2015]

gclient sync
Syncing projects: 100% (44/44), done.

________ running 'python3 src/build/mac_toolchain.py' in '/Users/mac/Downloads/github/webRtc'
/Users/mac/Downloads/github/webRtc/src/build/mac_toolchain.py:23: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
import pkg_resources
Skipping Mac toolchain installation for mac
Running hooks: 100% (30/30)
________ running 'python src/scripts/prepare_dev.py' in '/Users/mac/Downloads/github/webRtc'
Applying: Export WebRTC symbols on iOS.
Applying: Enable C++20 on iOS
Applying: Enable C++20 for all platforms but LaCrOS and Fuchsia.
Applying: Allow third-party repositories to disable C++20 for MSVC
Applying: Apply -Wno-shadow for clang only.
Applying: Fix FFMPEG config for MSVC build.
Applying: Getting install-build-deps to work on Ubuntu 22.04 LTS
Applying: Allow ffmpeg_branding == "OWT".
Applying: Add an GN variable for using BoringSSL.
Applying: Roll clang llvmorg-18-init-12938-geb1d5065.
Applying: Suppress some warnings for clang 18.
Running hooks: 100% (30/30), done.

python src/scripts/build.py --sio_root ~/Downloads/github/socket.io-client-cpp/lib
ERROR at //build/config/compiler/BUILD.gn:1343:22: Script returned non-zero exit code.
clang_revision = exec_script("//tools/clang/scripts/update.py",
^----------
Current dir: /Users/mac/Downloads/github/webRtc/src/out/Debug-device-arm64/
Command: python3 /Users/mac/Downloads/github/webRtc/src/tools/clang/scripts/update.py --print-revision --verify-version=18
Returned 1 and printed out:

The expected clang version is llvmorg-18-init-12938-geb1d5065-1 but the actual version is llvmorg-16-init-6578-g0d30e92f-1
Did you run "gclient sync"?

See //build/config/BUILDCONFIG.gn:332:3: which caused the file to be included.
"//build/config/compiler:chromium_code",
^--------------------------------------
I tried to change update.py but
It is not work, I don’t know why clang version is not match.