How to solve old GLIB error while installing "pygobject" using jhbuild

Question

I am trying to install pygobject using jhbuild. And I am getting this error:

configure: error: Package requirements (glib-2.0 >= 2.48.0) were not met:
Requested 'glib-2.0 >= 2.48.0' but version of GLib is 2.38.2

So, I have installed glib-2.0 from https://launchpad.net/ubuntu/%2Bsource/glib2.0 using

./configure
make
make install

After installing this library I have tried again and getting same error.

So I check this How to solve old GLIB error question. And tried setting two variables like this

export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig/
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

And than tried again but no luck :(

I am using Ubuntu 14.04 LTS.