Package: ruby-merb-core Version: 1.1.3+dfsg-3 The Merb project ceased in 2011, following its merge into Rails between 2008 - 2010 as Merb became the basis for Rails 3. The website merbivore.com is now a domain squatter link farm.
The package ruby-merb-core first appears in Wheezy, which was released in 2013, after the upstream project was already terminated. For whatever reason a dead package may have been added to Debian, at this point it really should be removed. All related *merb* ruby packages should be removed as well from upcoming and future releases.