Dependency hell refers to the practice of reusing code from various sources to keep programmers from having to "reinvent the wheel" for every application they write.

As a result many programs cannot be installed until some set of libraries is installed. Sometimes these libraries themselves will be dependent on some other library, and things can snowball from there.

Dependency

A DEPENDENCY X->Y IS SAID TO BE TRIVIAL DEPENDENCY IF Y IS A PROPER SUBSET OF X OTHERWISE NON TRIVIAL DEPENDENCY.

Dependency after birth.

A DEPENDENCY X->Y IS SAID TO BE TRIVIAL DEPENDENCY IF Y IS A PROPER SUBSET OF X OTHERWISE NON TRIVIAL DEPENDENCY.