Just FYI / FTR, tar2sqfs exists in squashfs-tools-ng. I haven't gotten it working with mmdebstrap yet, but this (below) is enough to show that the approach is sound. Further work can happen in squashfs-land, not mmdebstrap-land.
Trent W. Buck wrote: > 3. tar2squashfs is useful for this & other things. > I don't think it's possible, but I'll ask the squashfs people. squashfs-tools isn't the only squashfs-tools anymore, * squashfs-tools-ng https://lkml.org/lkml/2019/8/1/1154 https://github.com/AgentD/squashfs-tools-ng https://bugs.debian.org/932971 (wnpp ITP) * squashfskit https://bugs.debian.org/918480 Neither are in Debian yet. I grabbed squashfs-tools-ng and spent twenty minutes with it. * claims to solve tar2squashfs https://bugs.debian.org/942288 https://github.com/ plougher/squashfs-tools/issues/25 * claims to solve --one-file-system, too - yay! https://bugs.debian.org/586757 * This is working: tar c tmp.txt | ./tar2sqfs tmp.sq # generate from plain tar unsquashfs -ll tmp.sq # squashfs-tools can read it mount -o loop tmp.sq /mnt # linux 5.2 can mount it * This is *not* working: mmdebstrap ["go faster" options...] buster | ./tar2sqfs tmp2.sq # generate from mmdebstrap unsquashfs -ll tmp2.sq # squashfs-tools can't read it mount -o loop tmp2.sq /mnt # linux 5.2 can mount it, but it's empty file tmp2.sq # header looks OK ./rdsquashfs --describe tmp2.sq # even squashfs-tools-ng can't read it ==> tmp2.sq: reading filesystem tree: location out of bounds. tar2sqfs can definitely see the files in the tar, because it prints their names to stderr as they go past. When I have more time, I'll try to debug this further.