When running sudo apt update on my Librem 5 (Birch), I get the following error :
E: Failed to fetch https://repo.pureos.net/pureos/dists/amber/main/binary-arm64/Packages lzma_read: Read error (7) E: Failed to fetch https://repo.pureos.net/pureos/dists/amber-phone/main/binary-arm64/Packages lzma_read: Read error (7) E: Failed to fetch https://repo.pureos.net/pureos/dists/amber-proposed-updates/main/binary-arm64/Packages lzma_read: Read error (7) E: Failed to fetch https://repo.pureos.net/pureos/dists/amber-phone-staging/main/i18n/Translation-en BZ2_bzread: /var/lib/apt/lists/partial/repo.pureos.net_pureos_dists_amber-phone-staging_main_i18n_Translation-en.bz2 Read error (-5: DATA_ERROR_MAGIC) E: Failed to fetch https://repo.pureos.net/pureos-debug/dists/amber-phone-staging-debug/main/binary-arm64/Packages lzma_read: Read error (7) E: Some index files failed to download. They have been ignored, or old ones used instead.
I have ran sudo apt clean followed by another sudo apt update but it didn't help.
It seems that this error is not frequent but someone on the forum already mentioned it : https://forums.puri.sm/t/lzma-read-read-error-7-from-apt-get-update/8294