JHBuild issue: Fail to build gnome-core, gnome-documents current glib version =< required

Hi,

I'm trying to build gnome-documents using JHBuild, the build fails 
because the glib version I have is lower then the glib version required 
for the build.

This is the first time I try to use JHBuild, and I'm quite confused...
 From the explanations in the wiki, jhbuild should check the build 
dependencies, download and build all the relevant packages needed for 
the package.

So how come I get messages that one of the dependencies are not up to 
date, and how come jhbuild try to build against my local glib and not 
try to download the appropriate package code and build against it ?

How can I overcome this issue?

Thanks,
Samuel