我尝试从 Pi 上新安装的 Ubuntu 上的启动器打开 Steam，它显示
Steam needs to install these additional packages:
libc6:arm64 libc6:i386 libegl1:arm64 libgbm1:arm64 libgl1-mesa-dri:arm64 libgl1-mesa-dri:i386 libgl1:arm64 libgl1:i386 steam-libs-amd64:amd64 steam-libs-i386:i386
Press return to proceed with the installation:
..............................................................E: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/mantic/restricted/binary-i386/Packages 404 Not Found [IP: 2620:2d:4000:1::19 80]
E: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/mantic-updates/restricted/binary-i386/Packages 404 Not Found [IP: 2620:2d:4000:1::19 80]
E: Failed to fetch http://ports.ubuntu.com/ubuntu-ports/dists/mantic-security/restricted/binary-i386/Packages 404 Not Found [IP: 2620:2d:4000:1::19 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package libc6:i386 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
libnss-nisplus libnss-nis libcrypt1 libc6-dev
Package libgl1:i386 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
Package libgl1-mesa-dri:i386 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
libgl1-amber-dri
E: Package 'libc6:i386' has no installation candidate
E: Package 'libgl1-mesa-dri:i386' has no installation candidate
E: Package 'libgl1:i386' has no installation candidate
Press return to continue:
我已经尝试过以前见过的所有解决方案。提前致谢。