> On closer inspection it appears I am actually running mawk:
> 
> $ awk -W version
> mawk 1.3.3 Nov 1996, Copyright (C) Michael D. Brennan

I see.

> Your supplied patch works and produces a correct MAKEDEV. Any idea what
> the problem is?

The substr()'s char position is 1 origin, 1 should be passed to mean
`from beginning of string'.

enami.