It's my fault, and I've just committed the following in src/UPDATING:

	no problem,

>20010726:
>	Texinfo was updated to 4.0.  To avoid failures when trying to
>	build the included texinfo files, use MKINFO=no before the new
>	makeinfo has been installed.
>
>How should this be done?

	or, if you are enough -current, this should work too.
	not sure about other inter-dependencies when upgrading from very very
	old NetBSD (like lack of libintl).

itojun

	Texinfo was updated to 4.0.  To avoid failures when trying to
	build the included texinfo files, perform the following prior
	to the build.
		% cd src/gnu/usr.bin/texinfo
		% make dependall
		# make install