Nixpkgs provides a large number of packages that can be used in various ways. In some cases you want to make modifications to a package.

In this post we'll go through various ways how modified packages can be used in the Nix ecosystem, how packages can be modified and finally show some common use-cases:

• Use a different version of a package
• Use local source code for package
• Use a different dependency for a single package
• Apply a security patch system-wide