Error: librsync support

I am getting "Error while saving ... : librsync support"  when trying
to use --delta sig. 

My dar --version out says:

$ dar --version

 dar version 2.6.2, Copyright (C) 2002-2019 Denis Corbin
   Long options support         : YES

 Using libdar 6.0.2 built with compilation time options:
   Libz compression (gzip)      : YES
   Libbz2 compression (bzip2)   : YES
   Liblzo2 compression (lzo)    : YES
   Liblzma compression (xz)     : YES
   Strong encryption (libgcrypt): YES
   Public key ciphers (gpgme)   : YES
   Extended Attributes support  : YES
   Large files support (> 2GB)  : YES
   ext2fs NODUMP flag support   : YES
   Integer size used            : 64 bits
   Thread safe support          : YES
   Furtive read mode support    : YES
   Linux ext2/3/4 FSA support   : YES
   Mac OS X HFS+ FSA support    : NO
   Detected system/CPU endian   : little
   Posix fadvise support        : YES
   Large dir. speed optimi.     : YES
   Timestamp read accuracy      : 1 microsecond
   Timestamp write accuracy     : 1 microsecond
   Restores dates of symlinks   : YES
   Multiple threads (libthreads): NO 
   Delta compression support    : NO
   Remote repository support    : NO

 compiled the Mar 11 2019 with GNUC version 8.3.0
 dar is part of the Disk ARchive suite (Release 2.6.2)
 dar comes with ABSOLUTELY NO WARRANTY; for details
 type `dar -W'. This is free software, and you are welcome
 to redistribute it under certain conditions; type `dar -L | more'
 for details.

How do I get a version of dar with "Delta compression support"?  Do I
have to build one myself?

I am using Debian (stable) 10.9.