nix-daemon.nix: Drop Nix 1.x compatibility

Probably didn't work anyway anymore.

nixos/modules/services/misc/nix-daemon.nix

@@ -10,7 +10,6 @@ let
 
   nixVersion = getVersion nix;
 
-  isNix20 = versionAtLeast nixVersion "2.0pre";
   isNix23 = versionAtLeast nixVersion "2.3pre";
 
   makeNixBuildUser = nr:
@@ -28,39 +27,26 @@ let
   nixbldUsers = map makeNixBuildUser (range 1 cfg.nrBuildUsers);
 
   nixConf =
-    let
+    assert versionAtLeast nixVersion "2.2";
-      # In Nix < 2.0, If we're using sandbox for builds, then provide
+    pkgs.runCommand "nix.conf" { preferLocalBuild = true; extraOptions = cfg.extraOptions; } (
-      # /bin/sh in the sandbox as a bind-mount to bash. This means we
+      ''
-      # also need to include the entire closure of bash. Nix >= 2.0
-      # provides a /bin/sh by default.
-      sh = pkgs.runtimeShell;
-      binshDeps = pkgs.writeReferencesToFile sh;
-    in
-      pkgs.runCommand "nix.conf" { preferLocalBuild = true; extraOptions = cfg.extraOptions; } (''
-        ${optionalString (!isNix20) ''
-          extraPaths=$(for i in $(cat ${binshDeps}); do if test -d $i; then echo $i; fi; done)
-        ''}
         cat > $out <<END
         # WARNING: this file is generated from the nix.* options in
         # your NixOS configuration, typically
         # /etc/nixos/configuration.nix.  Do not edit it!
         build-users-group = nixbld
-        ${if isNix20 then "max-jobs" else "build-max-jobs"} = ${toString (cfg.maxJobs)}
+        max-jobs = ${toString (cfg.maxJobs)}
-        ${if isNix20 then "cores" else "build-cores"} = ${toString (cfg.buildCores)}
+        cores = ${toString (cfg.buildCores)}
-        ${if isNix20 then "sandbox" else "build-use-sandbox"} = ${if (builtins.isBool cfg.useSandbox) then boolToString cfg.useSandbox else cfg.useSandbox}
+        sandbox = ${if (builtins.isBool cfg.useSandbox) then boolToString cfg.useSandbox else cfg.useSandbox}
-        ${if isNix20 then "extra-sandbox-paths" else "build-sandbox-paths"} = ${toString cfg.sandboxPaths} ${optionalString (!isNix20) "/bin/sh=${sh} $(echo $extraPaths)"}
+        extra-sandbox-paths = ${toString cfg.sandboxPaths}
-        ${if isNix20 then "substituters" else "binary-caches"} = ${toString cfg.binaryCaches}
+        substituters = ${toString cfg.binaryCaches}
-        ${if isNix20 then "trusted-substituters" else "trusted-binary-caches"} = ${toString cfg.trustedBinaryCaches}
+        trusted-substituters = ${toString cfg.trustedBinaryCaches}
-        ${if isNix20 then "trusted-public-keys" else "binary-cache-public-keys"} = ${toString cfg.binaryCachePublicKeys}
+        trusted-public-keys = ${toString cfg.binaryCachePublicKeys}
         auto-optimise-store = ${boolToString cfg.autoOptimiseStore}
-        ${if isNix20 then ''
+        require-sigs = ${if cfg.requireSignedBinaryCaches then "true" else "false"}
-          require-sigs = ${if cfg.requireSignedBinaryCaches then "true" else "false"}
-        '' else ''
-          signed-binary-caches = ${if cfg.requireSignedBinaryCaches then "*" else ""}
-        ''}
         trusted-users = ${toString cfg.trustedUsers}
         allowed-users = ${toString cfg.allowedUsers}
-        ${optionalString (isNix20 && !cfg.distributedBuilds) ''
+        ${optionalString (!cfg.distributedBuilds) ''
           builders =
         ''}
         system-features = ${toString cfg.systemFeatures}
@@ -422,8 +408,7 @@ in
 
     systemd.services.nix-daemon =
       { path = [ nix pkgs.utillinux config.programs.ssh.package ]
-          ++ optionals cfg.distributedBuilds [ pkgs.gzip ]
+          ++ optionals cfg.distributedBuilds [ pkgs.gzip ];
-          ++ optionals (!isNix20) [ pkgs.openssl.bin ];
 
         environment = cfg.envVars
           // { CURL_CA_BUNDLE = "/etc/ssl/certs/ca-certificates.crt"; }
@@ -440,34 +425,13 @@ in
         restartTriggers = [ nixConf ];
       };
 
-    nix.envVars =
-      optionalAttrs (!isNix20) {
-        NIX_CONF_DIR = "/etc/nix";
-
-        # Enable the copy-from-other-stores substituter, which allows
-        # builds to be sped up by copying build results from remote
-        # Nix stores.  To do this, mount the remote file system on a
-        # subdirectory of /run/nix/remote-stores.
-        NIX_OTHER_STORES = "/run/nix/remote-stores/*/nix";
-      }
-
-      // optionalAttrs (cfg.distributedBuilds && !isNix20) {
-        NIX_BUILD_HOOK = "${nix}/libexec/nix/build-remote.pl";
-      };
-
     # Set up the environment variables for running Nix.
     environment.sessionVariables = cfg.envVars //
       { NIX_PATH = cfg.nixPath;
       };
 
-    environment.extraInit = optionalString (!isNix20)
+    environment.extraInit =
       ''
-        # Set up secure multi-user builds: non-root users build through the
-        # Nix daemon.
-        if [ "$USER" != root -o ! -w /nix/var/nix/db ]; then
-            export NIX_REMOTE=daemon
-        fi
-      '' + ''
         if [ -e "$HOME/.nix-defexpr/channels" ]; then
           export NIX_PATH="$HOME/.nix-defexpr/channels''${NIX_PATH:+:$NIX_PATH}"
         fi