irb1.8 software package provides virtual package provided by ruby1.8, 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 irb1.8
irb1.8 is installed in your system.
Make ensure the irb1.8 package were installed using the commands given below,
$ sudo dpkg-query -l | grep irb1.8*
You will get with irb1.8 package name, version, architecture and description in a table
| Distro | Debian 7 wheezy |
| Section | Virtual packages |
| Package | irb1.8 |
| Version | |
| Description | virtual package provided by ruby1.8 |
| Sub Section | virtual |