Error building with MS-SNTP

$ ./waf configure --enable-mssntp clean build
[112/139] Compiling ntpd/ntpd.c
../../ntpd/ntp_signd.c:212:49: error: use of undeclared identifier 'xpkt0'; did you mean 'xpkt'?
                                sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, xpkt0, sendlen);
                                                                            ^~~~~
                                                                            xpkt
../../ntpd/ntp_signd.c:120:15: note: 'xpkt' declared here
        struct pkt  *xpkt
                     ^
1 error generated.

Waf: Leaving directory `/Users/selsky/src/gitlab.com/ntpsec/build/main'
Build failed
 -> task in 'ntpd' failed with exit status 1 (run with -v to display more information)

cc: @hal.murray