Usage: mkcomposefs [OPTIONS] SOURCE IMAGE
Options:
  --digest-store=PATH   Store content files in this directory
  --use-epoch           Make all mtimes zero
  --skip-devices        Don't store device nodes
  --skip-xattrs         Don't store file xattrs
  --user-xattrs         Only store user.* xattrs
  --print-digest        Print the digest of the image
  --print-digest-only   Print the digest of the image, don't write image
  --from-file           The source is a dump file, not a directory
  --min-version=N       Use this minimal format version (default=0)
  --max-version=N       Use this maxium format version (default=1)
  --threads=N           Use this to override the default number of threads used to calculate digest and copy files (default=64)