An interesting observation, as there are other unexpected empty lines (indicating a new block) in 'provides.db':
tc@box:~$ grep -A1 "^$" provides.db | grep -vE "^(--|)$" | grep -v "\.tcz$"
squashfs-root
squashfs-root
squashfs-root
squashfs-root
squashfs-root
lib
A closer look shows that there are quite a few directories listed (e.g. 'etc' or 'lib') or sequences like: Parallel unsquashfs: Using 4 processors
2 inodes (160 blocks) to write