[LRUG] Middleman slow. Am I missing something?

[gvim]

 From the source directory of my Middleman project:

../bin/middleman build --no-clean -g index.html

.... takes 2.24 seconds

I switched from Perl to Ruby a couple of years ago but with Perl's 
Template::Toolkit, which is by no means a lightweight library, the same 
processs:

ttree -f ../tt/ttree.cfg index.sht

... takes 0.13 seconds.

Am I missing an option or something?

gvim