struct.error: unpack_from requires a buffer of at least 12 bytes for unpacking 12 bytes at offset 0 (actual buffer size is 0)

[gingerbeardman]

Error

Traceback (most recent call last):
  File "/Volumes/External/Users/matt/CD-ROMs/./dumper-companion.py", line 518, in <module>
    exit(args.func(args))
  File "/Volumes/External/Users/matt/CD-ROMs/./dumper-companion.py", line 302, in extract_volume
    vol.read(source_volume.read_bytes())
  File "/usr/local/lib/python3.9/site-packages/machfs/main.py", line 226, in read
    for rec in btree.dump_btree(getfork(drXTFlSize, drXTExtRec, 3, 'data')):
  File "/usr/local/lib/python3.9/site-packages/machfs/btree.py", line 87, in dump_btree
    ndFLink, ndBLink, ndType, ndNHeight, (header_rec, unused_rec, map_rec) = _unpack_btree_node(buf, 0)
  File "/usr/local/lib/python3.9/site-packages/machfs/btree.py", line 57, in _unpack_btree_node
    ndFLink, ndBLink, ndType, ndNHeight, ndNRecs = struct.unpack_from('>LLBBH', buf, start)
struct.error: unpack_from requires a buffer of at least 12 bytes for unpacking 12 bytes at offset 0 (actual buffer size is 0)

Notes

• I'm using machfs via SCUMMVM's dumper-companion.py, forgive me if this is their problem
• I've dumped the disc multiple times just to make sure it's legit
• disc is HFS with MacJapanese filenames

CD-ROM ISO

• available on request