Translations:FAQ/88/en

First try to update the local nixpkgs expressions with nix-channel --update (these describe where to download sources from and how to build them). Try your build again and the url might have already been correctly updated for the package in question. You can also subscribe the unstable channel (which includes the most up-to-date expressions) with nix-channel --add http://nixos.org/channels/nixpkgs-unstable, update and try the build again.