man(1) and port-specific pages

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

Hello,
trying to configure power management on my system running netbsd-6 I ran
into:
pop:/users/cao/bouyer>man powernow
man: no entry for powernow in the manual.

the page is present:
pop:/users/cao/bouyer>ls -l /usr/share/man/man4/x86/powernow.4 
-r--r--r--  1 root  wheel  2495 Mar  3 18:11 /usr/share/man/man4/x86/powernow.4

and has even been indexed:
pop:/users/cao/bouyer>man -k powernow
powernow(4)     AMD PowerNow! and Cool'n'Quiet
The powernow driver supports AMD PowerNow! and Cool'n'Quiet CPU frequency 
scaling technologies. The following sysctl(8) variables are available with 
powernow : machdep.powernow.frequency.target The target frequency of the CPUs . 
machdep.powernow.frequency.current The current frequency...

/etc/man.conf is from the distribution, and there is no $MANPATH.

Any idea ?

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--