[Solved] The recently updated CUDA repo for Ubuntu 22.04 is broken

the metadata in the InRelease file is inconsistent with the Packages.gz file, which causes a failure when executing apt update

➜  ~ cat /etc/apt/sources.list.d/cuda-ubuntu2204-x86_64.list
deb [signed-by=/usr/share/keyrings/cuda-archive-keyring.gpg] https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2204/x86_64/ /
➜  ~ sudo apt update
Hit:1 http://security.ubuntu.com/ubuntu jammy-security InRelease
Get:3 https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2204/x86_64  InRelease [1,581 B]
Get:7 https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2204/x86_64  Packages [1,283 kB]
Ign:7 https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2204/x86_64  Packages
Err:7 https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2204/x86_64  Packages
  File has unexpected size (1268985 != 1283104). Mirror sync in progress? [IP: 59.36.216.28 443]
Err:7 https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2204/x86_64  Packages
  File has unexpected size (1268985 != 1283104). Mirror sync in progress? [IP: 59.36.216.28 443]
Fetched 1,581 B in 17s (94 B/s)
Reading package lists... Done
E: Failed to fetch https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2204/x86_64/Packages  File has unexpected size (1268985 != 1283104). Mirror sync in progress? [IP: 59.36.216.28 443]
E: Some index files failed to download. They have been ignored, or old ones used instead.

specifically, both the file size and md5sum of the Packages.gz file do not match the data in the InRelease file:

➜  ~ curl -sSfL https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2204/x86_64/InRelease
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Origin: NVIDIA
Label: NVIDIA CUDA
Architecture: x86_64
Date: Fri, 24 Jan 2025 00:19:29 +0000
MD5Sum:
 76429f6631935be6c3f72761c2407538                                          6363199 Packages
 8b249af0bbb06527949301d5f4e46074                                          1283104 Packages.gz
SHA1:
 86d87cfb7d38f39e5725c587a3cb7eab16a7d8b2                                  6363199 Packages
 ef50feb53cdfb7dccfc162a4b874360a4ad1cd99                                  1283104 Packages.gz
SHA256:
 971410a648b04b7c2f0e8e4b1e7195b23503866fac5bfa860b9640391f75ca96          6363199 Packages
 7dce84cf88287541a72a0a40dae41983ed1b1365b01eb794f9d9acfb6b40ddb7          1283104 Packages.gz
Acquire-By-Hash: no
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
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=5cca
-----END PGP SIGNATURE-----
➜  ~ curl -sSOL https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2204/x86_64/Packages.gz
➜  ~ ls -l Packages.gz
-rw-rw-r-- 1 terminus terminus 1268985  1月 24 12:48 Packages.gz
➜  ~ md5sum Packages.gz
f1309f3b62f3f831a7e351971fce21ff  Packages.gz

The Packages.gz is now the expected file and everything works now:

➜  ~ curl -sSOL https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2204/x86_64/Packages.gz
➜  ~ ls -l Packages.gz
-rw-rw-r-- 1 terminus terminus 1268985  1月 24 12:48 Packages.gz
➜  ~ md5sum Packages.gz
f1309f3b62f3f831a7e351971fce21ff  Packages.gz
➜  ~ curl -sSOL https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2204/x86_64/Packages.gz
➜  ~ md5sum Packages.gz
8b249af0bbb06527949301d5f4e46074  Packages.gz
➜  ~ ls -l Packages.gz
-rw-rw-r-- 1 terminus terminus 1283104  1月 24 13:06 Packages.gz

I assume it indeed was caused by a in-progress mirror sync, I’ll close this thread as solved.