> Or am I missing only something tiny?  Keep in mind that I'll need to
> do this (download sources, make appropriate preparations, compile ping
> and install) on three production NetBSD platforms: 1.6.1, 2.1 and 3.1.

I did miss something tiny.  Merely cutting and pasting the commands
spewed out by "make" ignoring the leading location of the gcc compiler
(the toolchain location, presumably) helped endlessly.

But in fact, the correct solution came  from Der Mouse: redirecting
</dev/null took care of the symptoms altogether, which seems obvious
on inspecting the sources.  It's a pity about the misleading error
message, while the "fixes" recommended may or may not suffice in all
cases.

Still, many thanks to all who offered their help.

++L