Thanks for your answer Dan.
I went through your advice, and I succeeded to install the "glib-2.0" package via aptitude, and I did a trick to get the ".pc" config file for the "gstreamer-1.0" package.
However, as in the first screenshot, there is a header error: "../gst-plugin/gst-audio-source.h:25:21: fatal error: gst/gst.h: No such file or directory".
From here, I understood that gstreamer were not correctly installed, I tried several install from different package managers, I got bench of files related to gstreamer, but I was not able to make it works.
I followed their installation instructions, and I moved all of their pkgconfig/* files + built gstreamer.
After that, I went through the "gst-plugin" again, and I finally got it working, the "make depend" and "make" run perfectly and give me the "libgstonlinegmmdecodefaster.so" library as output.
To test, I tried the "/egs/voxforge/gst_demo", and it sounds like everything were working too.
The only drawback into all of that is, I need to redo everything step by step, because I would like to create a script which install everything that I mentioned here to let the users run the script to install Kaldi with one command for my project.
Any advise for that? Do you think it's safe if I upload a big tarball on a server containing a pre-build version?
Best,
Louis.