libapt-pkg4.12 software package provides package managment runtime library, you can install in your Debian 7 (Wheezy) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libapt-pkg4.12
libapt-pkg4.12 is installed in your system.
Make ensure the libapt-pkg4.12 package were installed using the commands given below,
$ sudo dpkg-query -l | grep libapt-pkg4.12 *
You will get with libapt-pkg4.12 package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | Libraries |
| Package | libapt-pkg4.12 |
| Version | 0.9.7.9+deb7u7 |
| Description | package managment runtime library |
| Sub Section | libs |