This just started happening in the last few days. I also see this (after ignoring the apt-get update error, per a previous comment), what I believe is new behaviour with ‘run_dev.sh’.
> Reading package lists... Done
> E: Failed to fetch https://isaac.download.nvidia.com/isaac-ros/ubuntu/main/dists/focal/main/binary-amd64/Packages.gz File has unexpected size (499551 != 499404). Mirror sync in progress? [IP: 93.184.215.166 443]
> Hashes of expected file:
> - Filesize:499404 [weak]
> - SHA256:0bd951d8f3a67be2865c64c2d950577b2158395d8d7fb5ead5e98ea8b9c968f9
> - SHA1:5c3b1c5a796288db5c84c0be663012ad2deeaa11 [weak]
> - MD5Sum:2b6f13316f99af58757494902eb70c78 [weak]
> Release file created at: Thu, 30 Nov 2023 18:17:36 +0000
> E: Some index files failed to download. They have been ignored, or old ones used instead.