getting ports updated on an older FreeBSD (5.1)

[Mel Pilgrim]

On 2015-06-24 03:10, Thomas Mueller wrote:
> I was thinking about the possibility of building/upgrading the base
> FreeBSD from source by steps, such as 5.1 -> final 6-stable -> final
> 8-stable -> 10.1 or possibly FreeBSD-current.

The introduction of KSE happened in 5.x and IIRC a related ABI break 
starting with 5.4 means the only upgrade path from prior versions is a 
full reinstall because you can't cross-run kernel and userland.