Hey, please add a useflag to install libvmod_std or install it by default. It is required to build additional vmods, e.g. https://www.varnish-cache.org/utilities / https://github.com/varnish/libvmod-header
As discussed in irc, what you need is vmod.py. Please test varnish-3.0.5-r2 and make sure it gives you what you need. Reopen this bug if there's still more to be done.
actually please test varnish-3.0.5-r3 because of bug #498274