Dependency resolution with apt-get and apt Evolutionary Tale

Over the past 30 years, the apt family has played an important role in dependency resolution for Debian distros.

- Bruce Byfield

While Debian did not originate dependency resolution in Linux, it was the first major distribution to develop it to modern standards. As early as 1994, Debian was using dpkg, a low-level front end for libapt-pkg that freed package installation from dependency hell – the seemingly endless effort to provide all necessary dependencies for a new package. Debian even took the problem one step further, adding suggested packages: Those that enhanced a package but were not strictly necessary for basic functionality. Although universal today, at the time dependency resolution was so unusual that other developers joked that Debian coders ordered lunch by typing apt‑get sandwich. For ease of use, dpkg was soon supplemented by the even higher level apt‑get command, although dpkg is still used for installation of local packages. Since those early days, apt‑get has given rise to an entire ecosystem of utility scripts. In the past decade, the ecosystem became so complex that Ubuntu released apt, a simpler version of apt‑get aimed at beginners or casual users. Today, Debian package management has become a comprehensive system that continues to evolve, but one whose intricacies can sometimes be overwhelming.

apt-get vs. apt