How to build a specific library version with dub?

[martinm]

I'm trying to use wayland-d which depends on derelict-util-2.0.6.
DUB can't download the zip and fails.
I download the zip to ~/.dub/packages/derelict-util folder, unzip 
and build.
DUB builds **DerelictUtil.a ~master**.

Trying to rebuild wayland-d, DUB can't find 
**derelict-util-2.0.6** dependency.
*dub list | grep -i derelict* shows:
*derelict-util ~master 
~/.dub/packages/derelict-util-2.0.6/derelict-util/*
is there.

How can DUB build 2.0.6 version ?
*dub build library at 2.0.6* fails
*(1) : Error: Got JSON of type null_, expected object.*

How can I change registry and manually change **~master** to 
**2.0.6** ?

Why is DUB stupid program ?