ports problem in an old system ver 4.9

[David Banning]

I have an old FreeBSD 4.9 installation that I cannot upgrade.

I wanted to install something from the ports, but I am getting
this error on almost every port;

# make
===>  Vulnerability check disabled, database not found
===>  License check disabled, port has not defined LICENSE
===>  Extracting for rsnapshot-1.3.1
/sbin/sha256: not found
*** Error code 127

Stop in /usr/ports/sysutils/rsnapshot.


Wondering if anyone has an idea where to look.