squashfs-tools-4.4 (SOLVED)

Точно плохо искал! :) Вот тебе объясняют зачем это нужно:

6. Unsquashfs is now more strict about error handling
-----------------------------------------------------

Unsquashfs splits errors into two categories: fatal errors and non-fatal
errors.  In this release a significant number of errors that were previously
non-fatal have been hardened to fatal.

Fatal errors are those which cause Unsquashfs to abort instantly.
These are generally due to failure to read the filesystem (corruption),
and/or failure to write files to the output filesystem, due to I/O error
or out of space.  Generally anything which is unexpected is a fatal error.

Non-fatal errors are generally where support is lacking in the
output filesystem, and it can be considered to be an expected failure.
This includes the inability to write extended attributes (xattrs) to
a filesystem that doesn't support them, the inability to create files on
filesystem that doesn't support them (i.e. symbolic links on VFAT), and the
inability to execute privileged operations as a user-process.

The user may well know the filesystem cannot support certain operations
and would prefer Unsquashfs to ignore then without aborting.

Т.е. цель была не скорость, а надёжность!

Ну и ещё:

Two new options have been added:

6.1. -ignore-errors

This makes Unsquashfs behave like previous versions, and treats more
errors as non-fatal.

6.2. -strict-errors

This makes Unsquashfs treat every error as fatal, and it will abort
instantly.

А ты -ignore-errors пробовал? Или "чукча не читатель..."(С)? ;)