It's similar with NixOS, patching a package is just adding a few lines in a persistent (and generally short) config file. You "only" pay for that patch by havin

It's similar with NixOS, patching a package is just adding a few lines in a persistent (and generally short) config file. You "only" pay for that patch by having to update it for newer versions and by compile time. The developer experience isn't as good as browser extensions yet, though. Iterating on a patch means downloading that package to a local directory and building it there, which won't be enough for, say, patches to system libraries. You have to actually apply the system configuration for that, which means recompiling.