Bash is slow. Supporting a nested inheritance structure on top of bash makes it even slower. Without metadata caches, processing ebuilds would be extraordinarily more painful than it already is. Imagine the extra time it would take to source all the ebuilds required to run a command such as emerge -e world before dependency resolution can begin.One of Gentoo’s major weaknesses is the lack of a shared implementation that natively supports bindings to other languages for core, specification-level features such as dependency format parsing. Due to this deficiency, over the years I’ve seen the same algorithms implemented in Python, C, Bash, Go, and more at varying levels of success.In the previous post on extending bash, using builtins was mentioned as a way to improve extensibility. Rather than writing native bash functions or spawning processes to run external tools, pkgcraft implements all its bash command support using builtins.Basing a package manager and related specification on bash is a mistake. Familiarity and hackability are great in the short-term, but as the novelty wears off it becomes clear that maintainability, efficiency, and other attributes hard to wrest from bash’s rigid design all suffer.