Comment 4 for bug 1380313

I found the problem.
gir1.2-caja package from LinuxMint (for example - http://packages.linuxmint.com/pool/upstream/c/caja/gir1.2-caja_1.8.1-1+qiana_all.deb ) and from MATE ppa (for example http://archive.ubuntu.com/ubuntu/pool/universe/c/caja/gir1.2-caja_1.8.2-1_i386.deb) have different file structure.

Mint - gir1.2-caja_1.8.1-1+qiana_all.deb:
   /usr/lib/girepository-1.0/Caja-2.0.typelib
   /usr/share/doc/gir1.2-caja/changelog.Debian.gz
   /usr/share/doc/gir1.2-caja/copyright
   /usr/share/gir-1.0/Caja-2.0.gir

PPA - gir1.2-caja_1.8.2-1_i386.deb:
   /usr/lib/i386-linux-gnu/girepository-1.0/Caja-2.0.typelib <- this path is wrong!
   /usr/share/doc/gir1.2-caja/changelog.Debian.gz
   /usr/share/doc/gir1.2-caja/copyright
   /usr/share/gir-1.0/Caja-2.0.gir

If I move /usr/lib/i386-linux-gnu/girepository-1.0/Caja-2.0.typelib to /usr/lib/girepository-1.0/Caja-2.0.typelib
I can import Caja from gi.repository in Ubuntu 14.10 MATE, Ubuntu 14.04.1 (with MATE PPAs), in Ubuntu 12.04.5 I got other error (not related to this bug).

So gir1.2-caja should be repacked (Caja-2.0.typelib should be placed in /usr/lib/girepository-1.0/ , not in /usr/lib/i386-linux-gnu/girepository-1.0/Caja-2.0.typelib ). Please make this change and bug will be fixed.