diff --git a/Makefile b/Makefile
index cab53d52a..e35aa89bc 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ export STOCKHOLM_VERSION ?= $(shell \
 system ?= $(HOSTNAME)
 $(if $(system),,$(error unbound variable: system))
 
-nixos-config ?= $(stockholm)/$(LOGNAME)/1systems/$(system).nix
+nixos-config ?= $(stockholm)/$(LOGNAME)/1systems/$(system)/config.nix
 ifneq ($(words $(wildcard $(nixos-config))),1)
 $(error bad nixos-config: $(nixos-config))
 endif
diff --git a/krebs/3modules/build.nix b/krebs/3modules/build.nix
index 976d378f9..904deb164 100644
--- a/krebs/3modules/build.nix
+++ b/krebs/3modules/build.nix
@@ -14,16 +14,9 @@ with import <stockholm/lib>;
       default = "/nix/var/nix/profiles/system";
     };
 
-    source = mkOption {
-      type = types.attrsOf types.source;
-      default = {};
-    };
-
     # TODO deprecate krebs.build.user
     user = mkOption {
       type = types.user;
     };
   };
-
-  config.krebs.build.source.stockholm.file = mkDefault (toString <stockholm>);
 }
diff --git a/krebs/5pkgs/simple/whatsupnix/whatsupnix.bash b/krebs/5pkgs/simple/whatsupnix/whatsupnix.bash
index 2ad9aadc9..e21e0f1b3 100644
--- a/krebs/5pkgs/simple/whatsupnix/whatsupnix.bash
+++ b/krebs/5pkgs/simple/whatsupnix/whatsupnix.bash
@@ -14,15 +14,30 @@
 #
 #   1     Usage error; arguments couldn't be parsed.
 #
-#   2     Build error; at least one failed derivation could be found.
+#   2     Nix error; input looks like Nix failed.
+#
+#   3     Build error; at least one failed derivation could be found.
 #
 
-failed_drvs=$(mktemp --tmpdir whatsupnix.XXXXXXXX)
-trap 'rm -f -- "$failed_drvs"' EXIT
+tmpdir=$(mktemp -d --tmpdir whatsupnix.XXXXXXXX)
+failed_drvs=$tmpdir/failed_drvs; touch "$failed_drvs"
+nix_errors=$tmpdir/nix_errors; touch "$nix_errors"
+cleanup() {
+  rm "$failed_drvs"
+  rm "$nix_errors"
+  rmdir "$tmpdir"
+}
+trap cleanup EXIT
 
 exec >&2
 
-gawk -v failed_drvs="$failed_drvs" '
+gawk \
+    -v failed_drvs="$failed_drvs" \
+    -v nix_errors="$nix_errors" \
+'
+  /^(\033\[31;1m)?error:/ {
+    print $0 >> nix_errors
+  }
   match($0, /^builder for ‘(\/nix\/store\/[^’]+\.drv)’ failed/, m) {
     print m[1] >> failed_drvs
   }
@@ -73,8 +88,10 @@ while read -r drv; do
   echo
 done < "$failed_drvs"
 
-if test -s "$failed_drvs"; then
+if test -s "$nix_errors"; then
   exit 2
+elif test -s "$failed_drvs"; then
+  exit 3
 else
   exit 0
 fi
diff --git a/lass/1systems/cloudkrebs.nix b/lass/1systems/cloudkrebs/config.nix
similarity index 53%
rename from lass/1systems/cloudkrebs.nix
rename to lass/1systems/cloudkrebs/config.nix
index e65b13d00..aa9a1f1ab 100644
--- a/lass/1systems/cloudkrebs.nix
+++ b/lass/1systems/cloudkrebs/config.nix
@@ -1,18 +1,17 @@
 { config, lib, pkgs, ... }:
 
 let
-  inherit (import ../4lib { inherit pkgs lib; }) getDefaultGateway;
-
+  inherit (import <stockholm/lass/4lib> { inherit pkgs lib; }) getDefaultGateway;
   ip = config.krebs.build.host.nets.internet.ip4.addr;
 in {
   imports = [
-    ../.
-    ../2configs/retiolum.nix
-    ../2configs/os-templates/CAC-CentOS-7-64bit.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/git.nix
-    ../2configs/realwallpaper.nix
-    ../2configs/privoxy-retiolum.nix
+    <stockholm/lass>
+    <stockholm/lass/2configs/retiolum.nix>
+    <stockholm/lass/2configs/os-templates/CAC-CentOS-7-64bit.nix>
+    <stockholm/lass/2configs/exim-retiolum.nix>
+    <stockholm/lass/2configs/git.nix>
+    <stockholm/lass/2configs/realwallpaper.nix>
+    <stockholm/lass/2configs/privoxy-retiolum.nix>
     {
       networking.interfaces.enp2s1.ip4 = [
         {
diff --git a/lass/1systems/cloudkrebs/source.nix b/lass/1systems/cloudkrebs/source.nix
new file mode 100644
index 000000000..99e71e755
--- /dev/null
+++ b/lass/1systems/cloudkrebs/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/lass/source.nix> {
+  name = "cloudkrebs";
+}
diff --git a/lass/1systems/dishfire.nix b/lass/1systems/dishfire/config.nix
similarity index 93%
rename from lass/1systems/dishfire.nix
rename to lass/1systems/dishfire/config.nix
index e12367aca..416edeb82 100644
--- a/lass/1systems/dishfire.nix
+++ b/lass/1systems/dishfire/config.nix
@@ -2,11 +2,10 @@
 
 {
   imports = [
-    ../.
-    ../2configs/retiolum.nix
+    <stockholm/lass>
+    <stockholm/lass/2configs/retiolum.nix>
     <nixpkgs/nixos/modules/profiles/qemu-guest.nix>
-    #../2configs/exim-retiolum.nix
-    ../2configs/git.nix
+    <stockholm/lass/2configs/git.nix>
     {
       boot.loader.grub = {
         device = "/dev/vda";
@@ -56,7 +55,7 @@
     }
     {
       imports = [
-        ../2configs/websites/fritz.nix
+        <stockholm/lass/2configs/websites/fritz.nix>
       ];
       krebs.iptables.tables.filter.INPUT.rules = [
          { predicate = "-p tcp --dport http"; target = "ACCEPT"; }
diff --git a/lass/1systems/dishfire/source.nix b/lass/1systems/dishfire/source.nix
new file mode 100644
index 000000000..2445af130
--- /dev/null
+++ b/lass/1systems/dishfire/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/lass/source.nix> {
+  name = "dishfire";
+}
diff --git a/lass/1systems/echelon.nix b/lass/1systems/echelon/config.nix
similarity index 74%
rename from lass/1systems/echelon.nix
rename to lass/1systems/echelon/config.nix
index da8864011..f064a4788 100644
--- a/lass/1systems/echelon.nix
+++ b/lass/1systems/echelon/config.nix
@@ -1,22 +1,20 @@
 { config, lib, pkgs, ... }:
 
 let
-  inherit (import ../4lib { inherit pkgs lib; }) getDefaultGateway;
-
+  inherit (import <stockholm/lass/4lib> { inherit pkgs lib; }) getDefaultGateway;
   ip = config.krebs.build.host.nets.internet.ip4.addr;
 in {
   imports = [
-    ../.
-    ../2configs/retiolum.nix
-    ../2configs/os-templates/CAC-CentOS-7-64bit.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/realwallpaper.nix
-    ../2configs/privoxy-retiolum.nix
-    ../2configs/git.nix
-    #../2configs/redis.nix
-    ../2configs/go.nix
-    ../2configs/ircd.nix
-    ../2configs/newsbot-js.nix
+    <stockholm/lass>
+    <stockholm/lass/2configs/retiolum.nix>
+    <stockholm/lass/2configs/os-templates/CAC-CentOS-7-64bit.nix>
+    <stockholm/lass/2configs/exim-retiolum.nix>
+    <stockholm/lass/2configs/realwallpaper.nix>
+    <stockholm/lass/2configs/privoxy-retiolum.nix>
+    <stockholm/lass/2configs/git.nix>
+    <stockholm/lass/2configs/go.nix>
+    <stockholm/lass/2configs/ircd.nix>
+    <stockholm/lass/2configs/newsbot-js.nix>
     {
       networking.interfaces.enp2s1.ip4 = [
         {
@@ -34,9 +32,6 @@ in {
       sound.enable = false;
     }
     {
-      imports = [
-        ../3modules/dnsmasq.nix
-      ];
       lass.dnsmasq = {
         enable = true;
         config = ''
diff --git a/lass/1systems/echelon/source.nix b/lass/1systems/echelon/source.nix
new file mode 100644
index 000000000..96888d5a8
--- /dev/null
+++ b/lass/1systems/echelon/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/lass/source.nix> {
+  name = "echelon";
+}
diff --git a/lass/1systems/icarus.nix b/lass/1systems/icarus/config.nix
similarity index 73%
rename from lass/1systems/icarus.nix
rename to lass/1systems/icarus/config.nix
index 13c517e3b..791ce0f46 100644
--- a/lass/1systems/icarus.nix
+++ b/lass/1systems/icarus/config.nix
@@ -1,19 +1,18 @@
 { config, pkgs, ... }:
 
-with import <stockholm/lib>;
 {
   imports = [
-    ../.
-    ../2configs/retiolum.nix
-    ../2configs/hw/tp-x220.nix
-    ../2configs/git.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/baseX.nix
-    ../2configs/browsers.nix
-    ../2configs/programs.nix
-    ../2configs/fetchWallpaper.nix
-    ../2configs/backups.nix
-    ../2configs/games.nix
+    <stockholm/lass>
+    <stockholm/lass/2configs/retiolum.nix>
+    <stockholm/lass/2configs/hw/tp-x220.nix>
+    <stockholm/lass/2configs/git.nix>
+    <stockholm/lass/2configs/exim-retiolum.nix>
+    <stockholm/lass/2configs/baseX.nix>
+    <stockholm/lass/2configs/browsers.nix>
+    <stockholm/lass/2configs/programs.nix>
+    <stockholm/lass/2configs/fetchWallpaper.nix>
+    <stockholm/lass/2configs/backups.nix>
+    <stockholm/lass/2configs/games.nix>
   ];
 
   krebs.build.host = config.krebs.hosts.icarus;
diff --git a/lass/1systems/icarus/source.nix b/lass/1systems/icarus/source.nix
new file mode 100644
index 000000000..5b46a44f3
--- /dev/null
+++ b/lass/1systems/icarus/source.nix
@@ -0,0 +1,4 @@
+import <stockholm/lass/source.nix> {
+  name = "icarus";
+  secure = true;
+}
diff --git a/lass/1systems/iso.nix b/lass/1systems/iso.nix
index b45d5b228..820ef74b8 100644
--- a/lass/1systems/iso.nix
+++ b/lass/1systems/iso.nix
@@ -4,12 +4,11 @@ with import <stockholm/lib>;
 {
   imports = [
     <nixpkgs/nixos/modules/installer/cd-dvd/installation-cd-minimal.nix>
-    ../../krebs
-    ../3modules
-    ../5pkgs
-    ../2configs/mc.nix
-    ../2configs/nixpkgs.nix
-    ../2configs/vim.nix
+    <stockholm/krebs>
+    <stockholm/lass/3modules>
+    <stockholm/lass/5pkgs>
+    <stockholm/lass/2configs/mc.nix>
+    <stockholm/lass/2configs/vim.nix>
     {
       # /dev/stderr doesn't work. I don't know why
       # /proc/self doesn't seem to work correctly
diff --git a/lass/1systems/mors.nix b/lass/1systems/mors/config.nix
similarity index 83%
rename from lass/1systems/mors.nix
rename to lass/1systems/mors/config.nix
index 0bfd54515..bb0a4e23e 100644
--- a/lass/1systems/mors.nix
+++ b/lass/1systems/mors/config.nix
@@ -3,28 +3,27 @@
 with import <stockholm/lib>;
 {
   imports = [
-    ../.
-    ../2configs/retiolum.nix
-    ../2configs/hw/tp-x220.nix
-    ../2configs/baseX.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/programs.nix
-    ../2configs/bitcoin.nix
-    ../2configs/browsers.nix
-    ../2configs/games.nix
-    ../2configs/pass.nix
-    ../2configs/elster.nix
-    ../2configs/steam.nix
-    ../2configs/wine.nix
-    ../2configs/git.nix
-    ../2configs/virtualbox.nix
-    ../2configs/fetchWallpaper.nix
-    #../2configs/c-base.nix
-    ../2configs/mail.nix
-    ../2configs/repo-sync.nix
-    ../2configs/ircd.nix
-    ../2configs/logf.nix
-    ../2configs/syncthing.nix
+    <stockholm/lass>
+    <stockholm/lass/2configs/retiolum.nix>
+    <stockholm/lass/2configs/hw/tp-x220.nix>
+    <stockholm/lass/2configs/baseX.nix>
+    <stockholm/lass/2configs/exim-retiolum.nix>
+    <stockholm/lass/2configs/programs.nix>
+    <stockholm/lass/2configs/bitcoin.nix>
+    <stockholm/lass/2configs/browsers.nix>
+    <stockholm/lass/2configs/games.nix>
+    <stockholm/lass/2configs/pass.nix>
+    <stockholm/lass/2configs/elster.nix>
+    <stockholm/lass/2configs/steam.nix>
+    <stockholm/lass/2configs/wine.nix>
+    <stockholm/lass/2configs/git.nix>
+    <stockholm/lass/2configs/virtualbox.nix>
+    <stockholm/lass/2configs/fetchWallpaper.nix>
+    <stockholm/lass/2configs/mail.nix>
+    <stockholm/lass/2configs/repo-sync.nix>
+    <stockholm/lass/2configs/ircd.nix>
+    <stockholm/lass/2configs/logf.nix>
+    <stockholm/lass/2configs/syncthing.nix>
     {
       #risk of rain port
       krebs.iptables.tables.filter.INPUT.rules = [
diff --git a/lass/1systems/mors/source.nix b/lass/1systems/mors/source.nix
new file mode 100644
index 000000000..a9dfa2eb6
--- /dev/null
+++ b/lass/1systems/mors/source.nix
@@ -0,0 +1,4 @@
+import <stockholm/lass/source.nix> {
+  name = "mors";
+  secure = true;
+}
diff --git a/lass/1systems/prism.nix b/lass/1systems/prism/config.nix
similarity index 88%
rename from lass/1systems/prism.nix
rename to lass/1systems/prism/config.nix
index 531dec9df..9faa4d473 100644
--- a/lass/1systems/prism.nix
+++ b/lass/1systems/prism/config.nix
@@ -4,13 +4,9 @@ with import <stockholm/lib>;
 let
   ip = config.krebs.build.host.nets.internet.ip4.addr;
 
-  inherit (import <stockholm/lass/2configs/websites/util.nix> {inherit lib pkgs;})
-    manageCerts
-  ;
-
 in {
   imports = [
-    ../.
+    <stockholm/lass>
     {
       networking.interfaces.et0.ip4 = [
         {
@@ -26,33 +22,33 @@ in {
         SUBSYSTEM=="net", ATTR{address}=="54:04:a6:7e:f4:06", NAME="et0"
       '';
     }
-    ../2configs/retiolum.nix
-    ../2configs/exim-smarthost.nix
-    ../2configs/downloading.nix
-    ../2configs/ts3.nix
-    ../2configs/bitlbee.nix
-    ../2configs/weechat.nix
-    ../2configs/privoxy-retiolum.nix
-    ../2configs/radio.nix
-    ../2configs/buildbot-standalone.nix
-    ../2configs/repo-sync.nix
-    ../2configs/binary-cache/server.nix
-    ../2configs/iodined.nix
-    ../2configs/libvirt.nix
-    ../2configs/hfos.nix
-    ../2configs/makefu-sip.nix
-    ../2configs/monitoring/server.nix
-    ../2configs/monitoring/monit-alarms.nix
-    ../2configs/paste.nix
-    ../2configs/syncthing.nix
-    ../2configs/coders-irc.nix
-    ../2configs/ciko.nix
+    <stockholm/lass/2configs/retiolum.nix>
+    <stockholm/lass/2configs/exim-smarthost.nix>
+    <stockholm/lass/2configs/downloading.nix>
+    <stockholm/lass/2configs/ts3.nix>
+    <stockholm/lass/2configs/bitlbee.nix>
+    <stockholm/lass/2configs/weechat.nix>
+    <stockholm/lass/2configs/privoxy-retiolum.nix>
+    <stockholm/lass/2configs/radio.nix>
+    <stockholm/lass/2configs/buildbot-standalone.nix>
+    <stockholm/lass/2configs/repo-sync.nix>
+    <stockholm/lass/2configs/binary-cache/server.nix>
+    <stockholm/lass/2configs/iodined.nix>
+    <stockholm/lass/2configs/libvirt.nix>
+    <stockholm/lass/2configs/hfos.nix>
+    <stockholm/lass/2configs/makefu-sip.nix>
+    <stockholm/lass/2configs/monitoring/server.nix>
+    <stockholm/lass/2configs/monitoring/monit-alarms.nix>
+    <stockholm/lass/2configs/paste.nix>
+    <stockholm/lass/2configs/syncthing.nix>
+    <stockholm/lass/2configs/coders-irc.nix>
+    <stockholm/lass/2configs/ciko.nix>
     {
       lass.pyload.enable = true;
     }
     {
       imports = [
-        ../2configs/bepasty.nix
+        <stockholm/lass/2configs/bepasty.nix>
       ];
       krebs.bepasty.servers."paste.r".nginx.extraConfig = ''
         if ( $server_addr = "${config.krebs.build.host.nets.internet.ip4.addr}" ) {
@@ -170,8 +166,8 @@ in {
     }
     {
       imports = [
-        ../2configs/websites/domsen.nix
-        ../2configs/websites/lassulus.nix
+        <stockholm/lass/2configs/websites/domsen.nix>
+        <stockholm/lass/2configs/websites/lassulus.nix>
       ];
       krebs.iptables.tables.filter.INPUT.rules = [
          { predicate = "-p tcp --dport http"; target = "ACCEPT"; }
@@ -195,7 +191,7 @@ in {
     }
     {
       imports = [
-        ../2configs/realwallpaper.nix
+        <stockholm/lass/2configs/realwallpaper.nix>
       ];
       services.nginx.virtualHosts."lassul.us".locations."/wallpaper.png".extraConfig = ''
         alias /var/realwallpaper/realwallpaper.png;
diff --git a/lass/1systems/prism/source.nix b/lass/1systems/prism/source.nix
new file mode 100644
index 000000000..557fbf509
--- /dev/null
+++ b/lass/1systems/prism/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/lass/source.nix> {
+  name = "prism";
+}
diff --git a/lass/1systems/shodan.nix b/lass/1systems/shodan/config.nix
similarity index 84%
rename from lass/1systems/shodan.nix
rename to lass/1systems/shodan/config.nix
index 044e2ccf8..a68471aa0 100644
--- a/lass/1systems/shodan.nix
+++ b/lass/1systems/shodan/config.nix
@@ -3,17 +3,17 @@
 with import <stockholm/lib>;
 {
   imports = [
-    ../.
-    ../2configs/retiolum.nix
-    ../2configs/hw/tp-x220.nix
-    ../2configs/baseX.nix
-    ../2configs/git.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/browsers.nix
-    ../2configs/programs.nix
-    ../2configs/fetchWallpaper.nix
-    ../2configs/backups.nix
-    ../2configs/wine.nix
+    <stockholm/lass>
+    <stockholm/lass/2configs/retiolum.nix>
+    <stockholm/lass/2configs/hw/tp-x220.nix>
+    <stockholm/lass/2configs/baseX.nix>
+    <stockholm/lass/2configs/git.nix>
+    <stockholm/lass/2configs/exim-retiolum.nix>
+    <stockholm/lass/2configs/browsers.nix>
+    <stockholm/lass/2configs/programs.nix>
+    <stockholm/lass/2configs/fetchWallpaper.nix>
+    <stockholm/lass/2configs/backups.nix>
+    <stockholm/lass/2configs/wine.nix>
     #{
     #  users.extraUsers = {
     #    root = {
diff --git a/lass/1systems/shodan/source.nix b/lass/1systems/shodan/source.nix
new file mode 100644
index 000000000..be24ae2d5
--- /dev/null
+++ b/lass/1systems/shodan/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/lass/source.nix> {
+  name = "shodan";
+}
diff --git a/lass/1systems/uriel.nix b/lass/1systems/uriel/config.nix
similarity index 95%
rename from lass/1systems/uriel.nix
rename to lass/1systems/uriel/config.nix
index b84fec317..70bef9883 100644
--- a/lass/1systems/uriel.nix
+++ b/lass/1systems/uriel/config.nix
@@ -4,9 +4,9 @@ with builtins;
 with import <stockholm/lib>;
 {
   imports = [
-    ../.
-    ../2configs/retiolum.nix
-    ../2configs/exim-retiolum.nix
+    <stockholm/lass>
+    <stockholm/lass/2configs/retiolum.nix>
+    <stockholm/lass/2configs/exim-retiolum.nix>
     {
       # locke config
       i18n.defaultLocale ="de_DE.UTF-8";
diff --git a/lass/1systems/uriel/source.nix b/lass/1systems/uriel/source.nix
new file mode 100644
index 000000000..11d6e1c34
--- /dev/null
+++ b/lass/1systems/uriel/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/lass/source.nix> {
+  name = "uriel";
+}
diff --git a/lass/2configs/default.nix b/lass/2configs/default.nix
index 161db9422..22a7b1c19 100644
--- a/lass/2configs/default.nix
+++ b/lass/2configs/default.nix
@@ -6,7 +6,6 @@ with import <stockholm/lib>;
     ../2configs/binary-cache/client.nix
     ../2configs/gc.nix
     ../2configs/mc.nix
-    ../2configs/nixpkgs.nix
     ../2configs/vim.nix
     ../2configs/monitoring/client.nix
     ./htop.nix
@@ -72,16 +71,7 @@ with import <stockholm/lib>;
   krebs = {
     enable = true;
     search-domain = "r";
-    build = {
-      user = config.krebs.users.lass;
-      source = let inherit (config.krebs.build) host; in {
-        nixos-config.symlink = "stockholm/lass/1systems/${host.name}.nix";
-        secrets.file =
-          if getEnv "dummy_secrets" == "true"
-            then toString <stockholm/lass/2configs/tests/dummy-secrets>
-            else "/home/lass/secrets/${host.name}";
-      };
-    };
+    build.user = config.krebs.users.lass;
   };
 
   nix.useSandbox = true;
diff --git a/lass/2configs/nixpkgs.nix b/lass/2configs/nixpkgs.nix
deleted file mode 100644
index f5a3bbf88..000000000
--- a/lass/2configs/nixpkgs.nix
+++ /dev/null
@@ -1,8 +0,0 @@
-{ ... }:
-
-{
-  krebs.build.source.nixpkgs.git = {
-    url = https://cgit.lassul.us/nixpkgs;
-    ref = "d72efac";
-  };
-}
diff --git a/lass/3modules/default.nix b/lass/3modules/default.nix
index fd353e008..e7744395d 100644
--- a/lass/3modules/default.nix
+++ b/lass/3modules/default.nix
@@ -1,6 +1,7 @@
 _:
 {
   imports = [
+    ./dnsmasq.nix
     ./ejabberd
     ./folderPerms.nix
     ./hosts.nix
diff --git a/lass/source.nix b/lass/source.nix
new file mode 100644
index 000000000..a4e9d9d6a
--- /dev/null
+++ b/lass/source.nix
@@ -0,0 +1,24 @@
+with import <stockholm/lib>;
+host@{ name, secure ? false }: let
+  builder = if getEnv "dummy_secrets" == "true"
+              then "buildbot"
+              else "lass";
+  _file = <stockholm> + "/lass/1systems/${name}/source.nix";
+in
+  evalSource (toString _file) {
+    nixos-config.symlink = "stockholm/lass/1systems/${name}/config.nix";
+    secrets.file = getAttr builder {
+      buildbot = toString <stockholm/lass/2configs/tests/dummy-secrets>;
+      lass = "/home/lass/secrets/${name}";
+    };
+    stockholm.file = toString <stockholm>;
+    nixpkgs.git = {
+      url = https://cgit.lassul.us/nixpkgs;
+      # nixos-17.03
+      # + copytoram:
+      #   87a4615 & 334ac4f
+      # + acme permissions for groups
+      #   fd7a8f1
+      ref = "0aac3fc";
+    };
+  }
diff --git a/lib/default.nix b/lib/default.nix
index 803a614a1..4c54f60aa 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -1,6 +1,9 @@
 let
   nixpkgs-lib = import <nixpkgs/lib>;
   lib = with lib; nixpkgs-lib // builtins // {
+
+    evalSource = import ./eval-source.nix;
+
     git = import ./git.nix { inherit lib; };
     shell = import ./shell.nix { inherit lib; };
     types = nixpkgs-lib.types // import ./types.nix { inherit lib; };
diff --git a/lib/eval-source.nix b/lib/eval-source.nix
new file mode 100644
index 000000000..468fc92d1
--- /dev/null
+++ b/lib/eval-source.nix
@@ -0,0 +1,15 @@
+with import <stockholm/lib>;
+let
+  eval = _file: source: evalModules {
+    modules = singleton {
+      inherit _file;
+      imports = map (source: { inherit source; }) (toList source);
+      options.source = mkOption {
+        type = types.attrsOf types.source;
+        default = {};
+      };
+    };
+  };
+in
+  # This function's return value can be used as pkgs.populate input.
+  _file: source: (eval _file source).config.source
diff --git a/shared/1systems/test-all-krebs-modules.nix b/shared/1systems/test-all-krebs-modules/config.nix
similarity index 98%
rename from shared/1systems/test-all-krebs-modules.nix
rename to shared/1systems/test-all-krebs-modules/config.nix
index 39d7c494b..7ebcf3b50 100644
--- a/shared/1systems/test-all-krebs-modules.nix
+++ b/shared/1systems/test-all-krebs-modules/config.nix
@@ -3,7 +3,7 @@ let
   en = { enable = true;};
 in {
   imports = [
-    ../.
+    <stockholm/shared>
   ];
   krebs = {
     enable = true;
diff --git a/shared/1systems/test-all-krebs-modules/source.nix b/shared/1systems/test-all-krebs-modules/source.nix
new file mode 100644
index 000000000..58d72365f
--- /dev/null
+++ b/shared/1systems/test-all-krebs-modules/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/shared/source.nix> {
+  name = "test-all-krebs-modules";
+}
diff --git a/shared/1systems/test-arch.nix b/shared/1systems/test-arch/config.nix
similarity index 95%
rename from shared/1systems/test-arch.nix
rename to shared/1systems/test-arch/config.nix
index a13fea425..453483d48 100644
--- a/shared/1systems/test-arch.nix
+++ b/shared/1systems/test-arch/config.nix
@@ -2,7 +2,7 @@
 
 {
   imports = [
-    ../.
+    <stockholm/shared>
     {
       boot.loader.grub = {
         device = "/dev/sda";
diff --git a/shared/1systems/test-arch/source.nix b/shared/1systems/test-arch/source.nix
new file mode 100644
index 000000000..ca2305684
--- /dev/null
+++ b/shared/1systems/test-arch/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/shared/source.nix> {
+  name = "test-arch";
+}
diff --git a/shared/1systems/test-centos6.nix b/shared/1systems/test-centos6/config.nix
similarity index 83%
rename from shared/1systems/test-centos6.nix
rename to shared/1systems/test-centos6/config.nix
index ebcece383..a81ff7c51 100644
--- a/shared/1systems/test-centos6.nix
+++ b/shared/1systems/test-centos6/config.nix
@@ -7,8 +7,8 @@ let
   gw = "168.235.148.1";
 in {
   imports = [
-    ../.
-    ../2configs/os-templates/CAC-CentOS-6.5-64bit.nix
+    <stockholm/shared>
+    <stockholm/shared/2configs/os-templates/CAC-CentOS-6.5-64bit.nix>
     {
       networking.interfaces.enp11s0.ip4 = [
         {
diff --git a/shared/1systems/test-centos6/source.nix b/shared/1systems/test-centos6/source.nix
new file mode 100644
index 000000000..0c7c78ec0
--- /dev/null
+++ b/shared/1systems/test-centos6/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/shared/source.nix> {
+  name = "test-centos6";
+}
diff --git a/shared/1systems/test-centos7.nix b/shared/1systems/test-centos7.nix
deleted file mode 100644
index 9ea063c9b..000000000
--- a/shared/1systems/test-centos7.nix
+++ /dev/null
@@ -1,16 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let
-  inherit (lib) head;
-
-in {
-  imports = [
-    ../.
-    ../2configs/os-templates/CAC-CentOS-7-64bit.nix
-    ../2configs/temp/networking.nix
-    ../2configs/temp/dirs.nix
-  ];
-
-  sound.enable = false;
-  krebs.build.host = config.krebs.hosts.test-centos7;
-}
diff --git a/shared/1systems/test-centos7/config.nix b/shared/1systems/test-centos7/config.nix
new file mode 100644
index 000000000..58f99e87c
--- /dev/null
+++ b/shared/1systems/test-centos7/config.nix
@@ -0,0 +1,16 @@
+{ config, lib, pkgs, ... }:
+
+let
+  inherit (lib) head;
+
+in {
+  imports = [
+    <stockholm/shared>
+    <stockholm/shared/2configs/os-templates/CAC-CentOS-7-64bit.nix>
+    <stockholm/shared/2configs/temp/networking.nix>
+    <stockholm/shared/2configs/temp/dirs.nix>
+  ];
+
+  sound.enable = false;
+  krebs.build.host = config.krebs.hosts.test-centos7;
+}
diff --git a/shared/1systems/test-centos7/source.nix b/shared/1systems/test-centos7/source.nix
new file mode 100644
index 000000000..5144477fe
--- /dev/null
+++ b/shared/1systems/test-centos7/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/shared/source.nix> {
+  name = "test-centos7";
+}
diff --git a/shared/1systems/test-failing.nix b/shared/1systems/test-failing/config.nix
similarity index 83%
rename from shared/1systems/test-failing.nix
rename to shared/1systems/test-failing/config.nix
index fe1c2cb65..fb6a58397 100644
--- a/shared/1systems/test-failing.nix
+++ b/shared/1systems/test-failing/config.nix
@@ -2,7 +2,7 @@
 
 {
   imports = [
-    ../.
+    <stockholm/shared>
   ];
   programs.ssh.startAgent = true;
   programs.ssh.startAgent = false;
diff --git a/shared/1systems/test-failing/source.nix b/shared/1systems/test-failing/source.nix
new file mode 100644
index 000000000..3e17d0b52
--- /dev/null
+++ b/shared/1systems/test-failing/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/shared/source.nix> {
+  name = "test-failing";
+}
diff --git a/shared/1systems/test-minimal-deploy.nix b/shared/1systems/test-minimal-deploy/config.nix
similarity index 93%
rename from shared/1systems/test-minimal-deploy.nix
rename to shared/1systems/test-minimal-deploy/config.nix
index bec2b38d5..eab703671 100644
--- a/shared/1systems/test-minimal-deploy.nix
+++ b/shared/1systems/test-minimal-deploy/config.nix
@@ -1,7 +1,7 @@
 { config, pkgs, lib, ... }:
 {
   imports = [
-    ../.
+    <stockholm/shared>
   ];
   krebs = {
     enable = true;
diff --git a/shared/1systems/test-minimal-deploy/source.nix b/shared/1systems/test-minimal-deploy/source.nix
new file mode 100644
index 000000000..2368cdd49
--- /dev/null
+++ b/shared/1systems/test-minimal-deploy/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/shared/source.nix> {
+  name = "test-minimal-deploy";
+}
diff --git a/shared/1systems/wolf.nix b/shared/1systems/wolf/config.nix
similarity index 74%
rename from shared/1systems/wolf.nix
rename to shared/1systems/wolf/config.nix
index 584ee0373..636f8e822 100644
--- a/shared/1systems/wolf.nix
+++ b/shared/1systems/wolf/config.nix
@@ -4,24 +4,24 @@ let
 in
 {
   imports = [
-    ../.
+    <stockholm/shared>
     <nixpkgs/nixos/modules/profiles/qemu-guest.nix>
-    ../2configs/collectd-base.nix
-    ../2configs/central-stats-client.nix
-    ../2configs/save-diskspace.nix
+    <stockholm/shared/2configs/collectd-base.nix>
+    <stockholm/shared/2configs/central-stats-client.nix>
+    <stockholm/shared/2configs/save-diskspace.nix>
 
-    ../2configs/cgit-mirror.nix
-    ../2configs/graphite.nix
-    ../2configs/repo-sync.nix
-    ../2configs/shared-buildbot.nix
+    <stockholm/shared/2configs/cgit-mirror.nix>
+    <stockholm/shared/2configs/graphite.nix>
+    <stockholm/shared/2configs/repo-sync.nix>
+    <stockholm/shared/2configs/shared-buildbot.nix>
 
-    ../2configs/shack/worlddomination.nix
-    ../2configs/shack/drivedroid.nix
-    # ../2configs/shack/nix-cacher.nix
-    ../2configs/shack/mqtt_sub.nix
-    ../2configs/shack/muell_caller.nix
-    ../2configs/shack/radioactive.nix
-    ../2configs/shack/share.nix
+    <stockholm/shared/2configs/shack/worlddomination.nix>
+    <stockholm/shared/2configs/shack/drivedroid.nix>
+    # <stockholm/shared/2configs/shack/nix-cacher.nix>
+    <stockholm/shared/2configs/shack/mqtt_sub.nix>
+    <stockholm/shared/2configs/shack/muell_caller.nix>
+    <stockholm/shared/2configs/shack/radioactive.nix>
+    <stockholm/shared/2configs/shack/share.nix>
 
   ];
   # use your own binary cache, fallback use cache.nixos.org (which is used by
@@ -43,6 +43,7 @@ in
   };
 
   nix = {
+    # use the up to date prism cache
     binaryCaches = [
       "http://cache.prism.r"
       "https://cache.nixos.org/"
diff --git a/shared/1systems/wolf/source.nix b/shared/1systems/wolf/source.nix
new file mode 100644
index 000000000..d2bc4952a
--- /dev/null
+++ b/shared/1systems/wolf/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/shared/source.nix> {
+  name = "wolf";
+}
diff --git a/shared/2configs/default.nix b/shared/2configs/default.nix
index 398f125e4..2146f42e8 100644
--- a/shared/2configs/default.nix
+++ b/shared/2configs/default.nix
@@ -7,18 +7,6 @@ with import <stockholm/lib>;
 
   # TODO rename shared user to "krebs"
   krebs.build.user = mkDefault config.krebs.users.shared;
-  krebs.build.source = let inherit (config.krebs.build) host user; in {
-    nixos-config.symlink = "stockholm/${user.name}/1systems/${host.name}.nix";
-    nixpkgs.git = {
-      url = https://github.com/NixOS/nixpkgs;
-      ref = "72c9ed78d0b1d9d5f531805ddf5bf06bfd447614"; # nixos-17.03 @ 2017-06-17
-    };
-    secrets.file =
-      if getEnv "dummy_secrets" == "true"
-        then toString <stockholm/shared/6tests/data/secrets>
-        else "${getEnv "HOME"}/secrets/krebs/${host.name}";
-    stockholm.file = getEnv "PWD";
-  };
 
   networking.hostName = config.krebs.build.host.name;
 
diff --git a/shared/source.nix b/shared/source.nix
new file mode 100644
index 000000000..8ec9fbb6f
--- /dev/null
+++ b/shared/source.nix
@@ -0,0 +1,19 @@
+with import <stockholm/lib>;
+host@{ name, secure ? false }: let
+  builder = if getEnv "dummy_secrets" == "true"
+              then "buildbot"
+              else "shared";
+  _file = <stockholm> + "/shared/1systems/${name}/source.nix";
+in
+  evalSource (toString _file) {
+    nixos-config.symlink = "stockholm/shared/1systems/${name}/config.nix";
+    secrets.file = getAttr builder {
+      buildbot = toString <stockholm/shared/6tests/data/secrets>;
+      lass = "${getEnv "HOME"}/secrets/krebs/${host.name}";
+    };
+    stockholm.file = toString <stockholm>;
+    nixpkgs.git = {
+      url = https://github.com/NixOS/nixpkgs;
+      ref = "72c9ed78d0b1d9d5f531805ddf5bf06bfd447614"; # nixos-17.03 @ 2017-06-17
+    };
+  }
diff --git a/shell.nix b/shell.nix
index 3e7ba81c1..57957f823 100644
--- a/shell.nix
+++ b/shell.nix
@@ -43,9 +43,11 @@ let
   '';
 
   init.env = pkgs.writeText "init.env" /* sh */ ''
-    config=''${config-$LOGNAME/1systems/$system.nix}
+    config=''${config-$LOGNAME/1systems/$system/config.nix}
+    source=''${source-$LOGNAME/1systems/$system/source.nix}
 
     export config
+    export source
     export system
     export target
 
@@ -85,18 +87,19 @@ let
     };
     populate = pkgs.writeDash "init.env.populate" ''
       set -efu
-      ${pkgs.nix}/bin/nix-instantiate \
+      _source=$(${pkgs.nix}/bin/nix-instantiate \
           --eval \
           --json \
           --readonly-mode \
           --show-trace \
           --strict \
           -I nixos-config="$config" \
-          -E 'with import <stockholm>; config.krebs.build.source' \
-        |
+          "$source")
+      echo $_source |
       ${pkgs.populate}/bin/populate \
           "$target_user@$target_host:$target_port$target_path" \
         >&2
+      unset _source
     '';
     proxy = pkgs.writeDash "init.env.proxy" ''
       set -efu
@@ -109,7 +112,7 @@ let
         NIX_PATH=$(q "$target_path") \
         STOCKHOLM_VERSION=$STOCKHOLM_VERSION \
         nix-shell \
-            --command $(q \
+            --run $(q \
                 config=$config \
                 system=$system \
                 target=$target \
diff --git a/tv/1systems/alnus.nix b/tv/1systems/alnus/config.nix
similarity index 90%
rename from tv/1systems/alnus.nix
rename to tv/1systems/alnus/config.nix
index ef2a0500f..dd9e594fc 100644
--- a/tv/1systems/alnus.nix
+++ b/tv/1systems/alnus/config.nix
@@ -4,10 +4,10 @@ with import <stockholm/lib>;
 
 {
   imports = [
-    ../.
-    ../2configs/hw/x220.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/retiolum.nix
+    <stockholm/tv>
+    <stockholm/tv/2configs/hw/x220.nix>
+    <stockholm/tv/2configs/exim-retiolum.nix>
+    <stockholm/tv/2configs/retiolum.nix>
   ];
 
   # TODO remove non-hardware stuff from ../2configs/hw/x220.nix
@@ -58,7 +58,6 @@ with import <stockholm/lib>;
   krebs.build = {
     host = config.krebs.hosts.alnus;
     user = mkForce config.krebs.users.dv;
-    source.nixpkgs.git.ref = mkForce "9b948ea439ddbaa26740ce35543e7e35d2aa6d18";
   };
 
   networking.networkmanager.enable = true;
diff --git a/tv/1systems/alnus/source.nix b/tv/1systems/alnus/source.nix
new file mode 100644
index 000000000..c3ed4dcfb
--- /dev/null
+++ b/tv/1systems/alnus/source.nix
@@ -0,0 +1,4 @@
+import <stockholm/tv/source.nix> {
+  name = "alnus";
+  override.nixpkgs.git.ref = "9b948ea439ddbaa26740ce35543e7e35d2aa6d18";
+}
diff --git a/tv/1systems/caxi.nix b/tv/1systems/caxi/config.nix
similarity index 73%
rename from tv/1systems/caxi.nix
rename to tv/1systems/caxi/config.nix
index 59f3cd63a..b136d1ade 100644
--- a/tv/1systems/caxi.nix
+++ b/tv/1systems/caxi/config.nix
@@ -6,10 +6,10 @@ with import <stockholm/lib>;
   krebs.build.host = config.krebs.hosts.caxi;
 
   imports = [
-    ../.
-    ../2configs/hw/CAC-Developer-1.nix
-    ../2configs/fs/CAC-CentOS-7-64bit.nix
-    ../2configs/retiolum.nix
+    <stockholm/tv>
+    <stockholm/tv/2configs/hw/CAC-Developer-1.nix>
+    <stockholm/tv/2configs/fs/CAC-CentOS-7-64bit.nix>
+    <stockholm/tv/2configs/retiolum.nix>
   ];
 
   networking = let
diff --git a/tv/1systems/caxi/source.nix b/tv/1systems/caxi/source.nix
new file mode 100644
index 000000000..bc875b768
--- /dev/null
+++ b/tv/1systems/caxi/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/tv/source.nix> {
+  name = "caxi";
+}
diff --git a/tv/1systems/cd.nix b/tv/1systems/cd/config.nix
similarity index 71%
rename from tv/1systems/cd.nix
rename to tv/1systems/cd/config.nix
index 9f2cec574..f78bcafeb 100644
--- a/tv/1systems/cd.nix
+++ b/tv/1systems/cd/config.nix
@@ -6,11 +6,11 @@ with import <stockholm/lib>;
   krebs.build.host = config.krebs.hosts.cd;
 
   imports = [
-    ../.
-    ../2configs/hw/CAC-Developer-2.nix
-    ../2configs/fs/CAC-CentOS-7-64bit.nix
-    ../2configs/exim-smarthost.nix
-    ../2configs/retiolum.nix
+    <stockholm/tv>
+    <stockholm/tv/2configs/hw/CAC-Developer-2.nix>
+    <stockholm/tv/2configs/fs/CAC-CentOS-7-64bit.nix>
+    <stockholm/tv/2configs/exim-smarthost.nix>
+    <stockholm/tv/2configs/retiolum.nix>
   ];
 
   networking = {
diff --git a/tv/1systems/cd/source.nix b/tv/1systems/cd/source.nix
new file mode 100644
index 000000000..019e8bc22
--- /dev/null
+++ b/tv/1systems/cd/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/tv/source.nix> {
+  name = "cd";
+}
diff --git a/tv/1systems/mu.nix b/tv/1systems/mu/config.nix
similarity index 95%
rename from tv/1systems/mu.nix
rename to tv/1systems/mu/config.nix
index 3f3b2c2f4..239f333b5 100644
--- a/tv/1systems/mu.nix
+++ b/tv/1systems/mu/config.nix
@@ -4,11 +4,11 @@ with import <stockholm/lib>;
 
 {
   imports = [
-    ../../krebs
-    ../2configs
-    ../3modules
-    ../2configs/exim-retiolum.nix
-    ../2configs/retiolum.nix
+    <stockholm/krebs>
+    <stockholm/tv/2configs>
+    <stockholm/tv/3modules>
+    <stockholm/tv/2configs/exim-retiolum.nix>
+    <stockholm/tv/2configs/retiolum.nix>
   ];
 
   krebs.build.host = config.krebs.hosts.mu;
diff --git a/tv/1systems/mu/source.nix b/tv/1systems/mu/source.nix
new file mode 100644
index 000000000..7e148cf36
--- /dev/null
+++ b/tv/1systems/mu/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/tv/source.nix> {
+  name = "mu";
+}
diff --git a/tv/1systems/nomic.nix b/tv/1systems/nomic/config.nix
similarity index 77%
rename from tv/1systems/nomic.nix
rename to tv/1systems/nomic/config.nix
index 9b9502254..d0144986b 100644
--- a/tv/1systems/nomic.nix
+++ b/tv/1systems/nomic/config.nix
@@ -6,16 +6,16 @@ with import <stockholm/lib>;
   krebs.build.host = config.krebs.hosts.nomic;
 
   imports = [
-    ../.
-    ../2configs/hw/x220.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/gitrepos.nix
-    ../2configs/im.nix
-    ../2configs/mail-client.nix
-    ../2configs/nginx/public_html.nix
-    ../2configs/pulse.nix
-    ../2configs/retiolum.nix
-    ../2configs/xserver
+    <stockholm/tv>
+    <stockholm/tv/2configs/hw/x220.nix>
+    <stockholm/tv/2configs/exim-retiolum.nix>
+    <stockholm/tv/2configs/gitrepos.nix>
+    <stockholm/tv/2configs/im.nix>
+    <stockholm/tv/2configs/mail-client.nix>
+    <stockholm/tv/2configs/nginx/public_html.nix>
+    <stockholm/tv/2configs/pulse.nix>
+    <stockholm/tv/2configs/retiolum.nix>
+    <stockholm/tv/2configs/xserver>
   ];
 
   boot.initrd.luks = {
diff --git a/tv/1systems/nomic/source.nix b/tv/1systems/nomic/source.nix
new file mode 100644
index 000000000..f173b65a6
--- /dev/null
+++ b/tv/1systems/nomic/source.nix
@@ -0,0 +1,4 @@
+import <stockholm/tv/source.nix> {
+  name = "nomic";
+  secure = true;
+}
diff --git a/tv/1systems/test/source.nix b/tv/1systems/test/source.nix
new file mode 100644
index 000000000..f756b8586
--- /dev/null
+++ b/tv/1systems/test/source.nix
@@ -0,0 +1,3 @@
+import <stockholm/tv/source.nix> {
+  name = "test";
+}
diff --git a/tv/1systems/wu.nix b/tv/1systems/wu/config.nix
similarity index 88%
rename from tv/1systems/wu.nix
rename to tv/1systems/wu/config.nix
index 4b3bf8538..5b2542acd 100644
--- a/tv/1systems/wu.nix
+++ b/tv/1systems/wu/config.nix
@@ -6,17 +6,17 @@ with import <stockholm/lib>;
   krebs.build.host = config.krebs.hosts.wu;
 
   imports = [
-    ../.
-    ../2configs/hw/w110er.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/gitrepos.nix
-    ../2configs/im.nix
-    ../2configs/mail-client.nix
-    ../2configs/man.nix
-    ../2configs/nginx/public_html.nix
-    ../2configs/pulse.nix
-    ../2configs/retiolum.nix
-    ../2configs/xserver
+    <stockholm/tv>
+    <stockholm/tv/2configs/hw/w110er.nix>
+    <stockholm/tv/2configs/exim-retiolum.nix>
+    <stockholm/tv/2configs/gitrepos.nix>
+    <stockholm/tv/2configs/im.nix>
+    <stockholm/tv/2configs/mail-client.nix>
+    <stockholm/tv/2configs/man.nix>
+    <stockholm/tv/2configs/nginx/public_html.nix>
+    <stockholm/tv/2configs/pulse.nix>
+    <stockholm/tv/2configs/retiolum.nix>
+    <stockholm/tv/2configs/xserver>
     {
       environment.systemPackages = with pkgs; [
         # root
diff --git a/tv/1systems/wu/source.nix b/tv/1systems/wu/source.nix
new file mode 100644
index 000000000..2e9cdeb8a
--- /dev/null
+++ b/tv/1systems/wu/source.nix
@@ -0,0 +1,4 @@
+import <stockholm/tv/source.nix> {
+  name = "wu";
+  secure = true;
+}
diff --git a/tv/1systems/xu.nix b/tv/1systems/xu/config.nix
similarity index 86%
rename from tv/1systems/xu.nix
rename to tv/1systems/xu/config.nix
index d82f45ac0..2bffdddb3 100644
--- a/tv/1systems/xu.nix
+++ b/tv/1systems/xu/config.nix
@@ -6,18 +6,18 @@ with import <stockholm/lib>;
   krebs.build.host = config.krebs.hosts.xu;
 
   imports = [
-    ../.
-    ../2configs/hw/x220.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/gitconfig.nix
-    ../2configs/gitrepos.nix
-    ../2configs/mail-client.nix
-    ../2configs/man.nix
-    ../2configs/nginx/public_html.nix
-    ../2configs/pulse.nix
-    ../2configs/retiolum.nix
-    ../2configs/binary-cache
-    ../2configs/xserver
+    <stockholm/tv>
+    <stockholm/tv/2configs/hw/x220.nix>
+    <stockholm/tv/2configs/exim-retiolum.nix>
+    <stockholm/tv/2configs/gitconfig.nix>
+    <stockholm/tv/2configs/gitrepos.nix>
+    <stockholm/tv/2configs/mail-client.nix>
+    <stockholm/tv/2configs/man.nix>
+    <stockholm/tv/2configs/nginx/public_html.nix>
+    <stockholm/tv/2configs/pulse.nix>
+    <stockholm/tv/2configs/retiolum.nix>
+    <stockholm/tv/2configs/binary-cache>
+    <stockholm/tv/2configs/xserver>
     {
       environment.systemPackages = with pkgs; [
 
diff --git a/tv/1systems/xu/source.nix b/tv/1systems/xu/source.nix
new file mode 100644
index 000000000..46e1aee90
--- /dev/null
+++ b/tv/1systems/xu/source.nix
@@ -0,0 +1,4 @@
+import <stockholm/tv/source.nix> {
+  name = "xu";
+  secure = true;
+}
diff --git a/tv/1systems/zu.nix b/tv/1systems/zu/config.nix
similarity index 88%
rename from tv/1systems/zu.nix
rename to tv/1systems/zu/config.nix
index 4fae3ca75..d2aab8c51 100644
--- a/tv/1systems/zu.nix
+++ b/tv/1systems/zu/config.nix
@@ -12,16 +12,16 @@ with import <stockholm/lib>;
         default = {};
       };
     }
-    ../.
-    ../2configs/hw/x220.nix
-    ../2configs/exim-retiolum.nix
-    ../2configs/gitrepos.nix
-    ../2configs/mail-client.nix
-    ../2configs/man.nix
-    ../2configs/nginx/public_html.nix
-    ../2configs/pulse.nix
-    ../2configs/retiolum.nix
-    ../2configs/xserver
+    <stockholm/tv>
+    <stockholm/tv/2configs/hw/x220.nix>
+    <stockholm/tv/2configs/exim-retiolum.nix>
+    <stockholm/tv/2configs/gitrepos.nix>
+    <stockholm/tv/2configs/mail-client.nix>
+    <stockholm/tv/2configs/man.nix>
+    <stockholm/tv/2configs/nginx/public_html.nix>
+    <stockholm/tv/2configs/pulse.nix>
+    <stockholm/tv/2configs/retiolum.nix>
+    <stockholm/tv/2configs/xserver>
     {
       environment.systemPackages = with pkgs; [
 
diff --git a/tv/1systems/zu/source.nix b/tv/1systems/zu/source.nix
new file mode 100644
index 000000000..7a5c4f523
--- /dev/null
+++ b/tv/1systems/zu/source.nix
@@ -0,0 +1,4 @@
+import <stockholm/tv/source.nix> {
+  name = "zu";
+  secure = true;
+}
diff --git a/tv/2configs/default.nix b/tv/2configs/default.nix
index 3d95d6dee..07496fd1f 100644
--- a/tv/2configs/default.nix
+++ b/tv/2configs/default.nix
@@ -6,23 +6,7 @@ with import <stockholm/lib>;
 in {
   krebs.enable = true;
 
-  krebs.build = {
-    user = config.krebs.users.tv;
-    source = let inherit (config.krebs.build) host; in {
-      nixos-config.symlink = "stockholm/tv/1systems/${host.name}.nix";
-      secrets.file = getAttr builder {
-        buildbot = toString <stockholm/tv/dummy_secrets>;
-        tv = "/home/tv/secrets/${host.name}";
-      };
-      secrets-common.file = "/home/tv/secrets/common";
-      nixpkgs.git = {
-        url = https://github.com/NixOS/nixpkgs;
-        ref = "057f89b9344e5341796046f25ae4f269be6d4529"; # nixos-17.03
-      };
-    } // optionalAttrs host.secure {
-      secrets-master.file = "/home/tv/secrets/master";
-    };
-  };
+  krebs.build.user = config.krebs.users.tv;
 
   networking.hostName = config.krebs.build.host.name;
 
diff --git a/tv/2configs/hw/x220.nix b/tv/2configs/hw/x220.nix
index 6cc295dc5..e0a04e214 100644
--- a/tv/2configs/hw/x220.nix
+++ b/tv/2configs/hw/x220.nix
@@ -11,7 +11,7 @@
   networking.wireless.enable = true;
 
   # Required for Centrino.
-  hardware.enableAllFirmware = true;
+  hardware.enableRedistributableFirmware = true;
 
   hardware.opengl.extraPackages = [ pkgs.vaapiIntel pkgs.vaapiVdpau ];
 
diff --git a/tv/source.nix b/tv/source.nix
new file mode 100644
index 000000000..4ede976d3
--- /dev/null
+++ b/tv/source.nix
@@ -0,0 +1,27 @@
+with import <stockholm/lib>;
+host@{ name, secure ? false, override ? {} }: let
+  builder = if getEnv "dummy_secrets" == "true"
+              then "buildbot"
+              else "tv";
+  _file = <stockholm> + "/tv/1systems/${name}/source.nix";
+in
+  evalSource (toString _file) [
+    {
+      nixos-config.symlink = "stockholm/tv/1systems/${name}/config.nix";
+      nixpkgs.git = {
+        # nixos-17.03
+        ref = mkDefault "1b57bf274ae5c76e91b2b264d8aa8bfcecb72102";
+        url = https://github.com/NixOS/nixpkgs;
+      };
+      secrets.file = getAttr builder {
+        buildbot = toString <stockholm/tv/dummy_secrets>;
+        tv = "/home/tv/secrets/${name}";
+      };
+      secrets-common.file = "/home/tv/secrets/common";
+      stockholm.file = toString <stockholm>;
+    }
+    (mkIf secure {
+      secrets-master.file = "/home/tv/secrets/master";
+    })
+    override
+  ]