self: super: let prebuilt = self.stdenv.mkDerivation rec { pname = "iosevka-tv-1"; version = "15.6.3"; src = self.fetchurl { urls = [ "https://c.krebsco.de/iosevka-tv-1-${version}.tar.gz" "https://ni.krebsco.de/~tv/mirrors/iosevka/iosevka-tv-1-${version}.tar.gz" ]; hash = "sha256-88OfNUbuNbGx3hFzYZ+gAYgOWZ+A8IYo45I1n/qOyhM="; }; installPhase = '' mkdir $out mv * $out/ ''; }; in if super.iosevka.version == prebuilt.version then prebuilt else super.iosevka-tv-1