[NTG-context] ConTeXt Sources (MkII)

A question for the hardcore members. On http://wiki.contextgarden.net/Manuals I read: ConTeXt Sources (MkII) Apart from the manuals, the source files (especially, some of the old ones) contain excellent documentation and examples. If you want a pretty printed pdf of a source file, say core-rul.tex, you can type texmfstart texexec --module kpse:core-rul.tex But this apparently doesn’t work any more (i.e., I simply entered that line in the Mac terminal and nothing happened). Am I doing something wrong? Robert