So, I wanted to open a Zed encrypt (secure) archive, but Zed encrypt was not packaged in Nixpkgs (and thus available on NixOS). I could have used a virtual machine to install the provided Debian package, but it would have been over in 30 minutes. Instead, I decided to write a derivation: library path overwrite, library preload, C code for overloading syscalls and change hardcoded path, wrapper scripts: in short, it just works! It took about ~9 hours of work. Totally worth it. #shavingtheyak