There seems to be a problem on sup.netbsd.org, first noticed Saturday morning,
and persisting until now:

stdout:
SUP Upgrade of current-allsrc at Sun Apr 27 06:34:50 1997
SUP: Error receiving file from file server
SUP: Upgrade of current-allsrc aborted at Apr 27 06:34:50 1997
SUP: Aborted

stderr:
SUP 8.26 (4.3 BSD) for file /usr/local/etc/supfile at Apr 27 06:27:24
SUP: SCM GOAWAY We died trying to run gzip
SUP: Premature EOF on network input

Releases doc, othersrc, and security supped normally--only allsrc (of the 4
that I sup) fails.