`mb pull coder-arm64` fails: blob has 77 MiB trailing null padding

[bdougie]

Problem

mb pull coder-arm64 fails consistently with:

decompressing stereos.img.zst: writing ~/.config/mb/mixtapes/coder-arm64/latest/stereos.img: corrupt stream, did not find end of stream

Root cause

The stereos.img.zst blob at download.stereos.ai has 77.6 MiB of trailing null bytes appended after the actual zstd data:

• Actual zstd data: 640.0 MiB (671,088,640 bytes)
• Null padding: 77.6 MiB (81,373,008 bytes)
• Total blob size: 752,461,648 bytes

The manifest declares digest sha256:bf212e026f722ccccd30f273d363f9b8a7245516f7bc1e8d81db67b41245cdeb, but the blob being served has digest sha256:d335283a5c0c9fdeef22fe48740cb74d0c973b69373bef651e76aaac012a21e2.

The zstd decoder reads past the valid frames into the null padding and fails.

Verification

# Download blob directly with curl
curl -s "https://download.stereos.ai/v2/mixtapes/coder-arm64/blobs/sha256:bf212e..." -o blob.bin

# Confirm: magic bytes are valid zstd (0x28B52FFD), but decompression fails
xxd -l 4 blob.bin   # 28b5 2ffd
zstd -t blob.bin     # Decoding error (36) : Data corruption detected

# Digest mismatch
shasum -a 256 blob.bin  # d33528... (not bf212e...)

Fix

The coder-arm64:latest image needs to be re-pushed to the registry with the correct (unpadded) disk blob.

Context

Discovered while testing the pull flow for the docs PR (private repo link https://github.com/papercomputeco/stereos.ai/pull/16).

[linear]

PCC-313

[jpmcb]

Hmmm I'm getting the same:

❯ mb mixtapes pull coder-arm64
  ⣯ Pulling mixtape "coder-arm64"...    Selected raw disk format from index
    Downloading stereos.img.zst (717.6 MiB) -> decompressing to stereos.img
  ✗ Pulling mixtape "coder-arm64"... (56.1s)
  ✗ decompressing stereos.img.zst: writing /Users/jpmcb/.config/mb/mixtapes/coder-arm64/latest/stereos.img: corrupt stream, did not find end of stream

Not certain what happened here or why these would suddenly be corrupted. I'll rebuild and re-push.

[jpmcb]

The registry is in abit of a poor state since we don't yet have x86 runners and the build pipelines just name it coder.

So, to unblock you, you can run mb mixtape pull coder:latest and that's the default arm image.

❯ mb mixtapes pull coder:latest
  ⣽ Pulling mixtape "coder:latest"...    Selected raw disk format from index
    Downloading stereos.img.zst (716.9 MiB) -> decompressing to stereos.img
  ⣟ Pulling mixtape "coder:latest"...
  ⣾ Pulling mixtape "coder:latest"...
  ⣟ Pulling mixtape "coder:latest"...
  ⣯ Pulling mixtape "coder:latest"...    Downloading bzImage (57.6 MiB)
  ⡿ Pulling mixtape "coder:latest"...    Downloading initrd (22.4 MiB)
  ⣽ Pulling mixtape "coder:latest"...    Downloading cmdline (208 B)
  ⢿ Pulling mixtape "coder:latest"...    Downloading init (94 B)
  ⣯ Pulling mixtape "coder:latest"...    Downloading mixtape.toml (1.1 KiB)
  ✓ Pulling mixtape "coder:latest"... (146.5s)

❯ mb up
  ✓ Starting sandbox... (7.0s)

  ✓ Sandbox "main" launched

    ssh -p 62684 -i ~/.config/mb/vms/main/ssh_key admin@127.0.0.1
    mb ssh main

In your jcard, just reference the mixtape directly:

mixtape = "coder:latest"

[bdougie]

duplicate of papercomputeco/stereOS#26