Just trying to help out, only familiar with /usr/bin/deb2sce, never heard of sce-deb2sce but i see it's in prebuilt.
Installed it but it didn't appear to download anything:
tc@box:/usr/bin$ sce-import -n sce-deb2sce
Using the -u option.
debian
#################### 100.0% 29.4 kBps DONE
verifying download...checksum matches OK
used 11409408 local, fetched 0
Debian Index synced: debian_jessie_main_i386_Packages
#################### 100.0% 0.0 kBps DONE
verifying download...checksum matches OK
used 372736 local, fetched 0
Debian Security Index synced: debian_jessie_security_i386_Packages
Using the repo http://security.debian.org jessie main
Using the -n option.
Importing sce-deb2sce.
Using Package Index:
/etc/sysconfig/tcedir/import/debinx/debian_jessie_main_i386_Packages
Using Security Index:
/etc/sysconfig/tcedir/import/debinx/debian_jessie_security_i386_Packages
Using debian Mirror: http://ftp.ca.debian.org/debian
Using debian Security Mirror: http://ftp.ca.debian.org/debian
sce-deb2sce is a dCore premade package.
Gathering dependency info..
Parallel mksquashfs: Using 1 processor
Creating 4.0 filesystem on /etc/sysconfig/tcedir/sce/sce-deb2sce.sce, block size 4096.
Exportable Squashfs 4.0 filesystem, gzip compressed, data block size 4096
compressed data, compressed metadata, compressed fragments, no xattrs
duplicates are removed
Filesystem size 0.15 Kbytes (0.00 Mbytes)
99.37% of uncompressed filesystem size (0.15 Kbytes)
Inode table size 29 bytes (0.03 Kbytes)
85.29% of uncompressed inode table size (34 bytes)
Directory table size 0 bytes (0.00 Kbytes)
-nan% of uncompressed directory table size (0 bytes)
Number of duplicate files found 0
Number of inodes 1
Number of files 0
Number of fragments 0
Number of symbolic links 0
Number of device nodes 0
Number of fifo nodes 0
Number of socket nodes 0
Number of directories 1
Number of ids (unique uids + gids) 1
Number of uids 1
root (0)
Number of gids 1
root (0)
Finished importing sce-deb2sce.sce.
Moved to /tmp and tried to extract:
tc@box:/tmp$ unsquashfs sce-deb2sce.sce
Parallel unsquashfs: Using 1 processor
FATAL ERROR aborting: squashfs_opendir: directory block 0 not found!
Loaded sce-deb2sce and it's empty, not even a file system:
tc@box:/tmp/tcloop/sce-deb2sce$ ll
total 0