I did (cd /usr/src; ./build.sh -E build) and have a foonly fine system of
current, but I notice that my sendmail borked at boot, complaining that the
/etc/mail/sendmail.cf was for v9.

so I did manual stuff to upgrade (cd /usr/src/gnu/usr.sbin/sendmail/cf/cf;
make && make install) and it writes to /usr/share/sendmail, not /etc/mail/

hmm. Have I somehow missed a step in a critical bugfix/patch upgrade which
created the submit.mc and cf from the netbsd-msp.mc?

etcupdate didn't complain either.

cheers

-George