nix: remove unused unstable.nix file

pkgs/tools/package-management/nix/unstable.nix

@@ -1,76 +0,0 @@
-{ lib, stdenv, fetchurl, perl, curl, bzip2, sqlite, openssl ? null
-, pkgconfig, boehmgc, perlPackages, libsodium
-, storeDir ? "/nix/store"
-, stateDir ? "/nix/var"
-}:
-
-stdenv.mkDerivation rec {
-  name = "nix-1.9pre4100_4bbcfaf";
-
-  src = fetchurl {
-    url = "http://hydra.nixos.org/build/21565942/download/4/${name}.tar.xz";
-    sha256 = "1jcy0n8mi17k5vk89vammfh74lvsgnm4gjsk23cq1shspjnbbgxs";
-  };
-
-  nativeBuildInputs = [ perl pkgconfig ];
-
-  buildInputs = [ curl openssl sqlite ] ++ lib.optional stdenv.isLinux libsodium;
-
-  propagatedBuildInputs = [ boehmgc ];
-
-  # Note: bzip2 is not passed as a build input, because the unpack phase
-  # would end up using the wrong bzip2 when cross-compiling.
-  # XXX: The right thing would be to reinstate `--with-bzip2' in Nix.
-  postUnpack =
-    '' export CPATH="${bzip2.dev}/include"
-       export LIBRARY_PATH="${bzip2.out}/lib"
-       export CXXFLAGS="-Wno-error=reserved-user-defined-literal"
-    '';
-
-  configureFlags =
-    ''
-      --with-store-dir=${storeDir} --localstatedir=${stateDir} --sysconfdir=/etc
-      --with-dbi=${perlPackages.DBI}/${perl.libPrefix}
-      --with-dbd-sqlite=${perlPackages.DBDSQLite}/${perl.libPrefix}
-      --with-www-curl=${perlPackages.WWWCurl}/${perl.libPrefix}
-      --disable-init-state
-      --enable-gc
-    '';
-
-  makeFlags = "profiledir=$(out)/etc/profile.d";
-
-  installFlags = "sysconfdir=$(out)/etc";
-
-  doInstallCheck = true;
-
-  crossAttrs = {
-    postUnpack =
-      '' export CPATH="${bzip2.crossDrv}/include"
-         export NIX_CROSS_LDFLAGS="-L${bzip2.crossDrv}/lib -rpath-link ${bzip2.crossDrv}/lib $NIX_CROSS_LDFLAGS"
-      '';
-
-    configureFlags =
-      ''
-        --with-store-dir=${storeDir} --localstatedir=${stateDir}
-        --with-dbi=${perlPackages.DBI}/${perl.libPrefix}
-        --with-dbd-sqlite=${perlPackages.DBDSQLite}/${perl.libPrefix}
-        --with-www-curl=${perlPackages.WWWCurl}/${perl.libPrefix}
-        --disable-init-state
-        --enable-gc
-      '' + stdenv.lib.optionalString (
-          stdenv.cross ? nix && stdenv.cross.nix ? system
-      ) ''--with-system=${stdenv.cross.nix.system}'';
-
-    doInstallCheck = false;
-  };
-
-  enableParallelBuilding = true;
-
-  meta = {
-    description = "The Nix Deployment System";
-    homepage = http://nixos.org/;
-    license = stdenv.lib.licenses.lgpl2Plus;
-    maintainers = [ stdenv.lib.maintainers.eelco ];
-    platforms = stdenv.lib.platforms.all;
-  };
-}