> .
>
> trying to install suse91_base from pkgsrc (package already prepared)
>
> /usr/pkg/emul/linux/sbin/ldconfig -r /usr/pkg/emul/linux
> FATAL: kernel too old
>
>
> any idea? looks like strange problem as package is already prepared...

You need to do:

sysctl -w emul.linux.kern.osrelease=2.6.30

..and then try again.

COMPAT_LINUX for amd64 is still "experimental", though it should work 
for a lot of things. One problem is likely to be programs that use the 
newer Linux thread library.

- Frank