Merge branch 'master' into staging

Resolved the following conflicts (by carefully applying patches from the both
branches since the fork point):

   pkgs/development/libraries/epoxy/default.nix
   pkgs/development/libraries/gtk+/3.x.nix
   pkgs/development/python-modules/asgiref/default.nix
   pkgs/development/python-modules/daphne/default.nix
   pkgs/os-specific/linux/systemd/default.nix

nixos/modules/system/activation/activation-script.nix

@@ -117,14 +117,7 @@ in
 
   config = {
 
-    system.activationScripts.stdio =
-      ''
-        # Needed by some programs.
-        ln -sfn /proc/self/fd /dev/fd
-        ln -sfn /proc/self/fd/0 /dev/stdin
-        ln -sfn /proc/self/fd/1 /dev/stdout
-        ln -sfn /proc/self/fd/2 /dev/stderr
-      '';
+    system.activationScripts.stdio = ""; # obsolete
 
     system.activationScripts.var =
       ''

nixos/modules/system/boot/initrd-network.nix

@@ -23,6 +23,8 @@ let
       fi
     '';
 
+  udhcpcArgs = toString cfg.udhcpc.extraArgs;
+
 in
 
 {
@@ -47,6 +49,16 @@ in
       '';
     };
 
+    boot.initrd.network.udhcpc.extraArgs = mkOption {
+      default = [];
+      type = types.listOf types.str;
+      description = ''
+        Additional command-line arguments passed verbatim to udhcpc if
+        <option>boot.initrd.network.enable</option> and <option>networking.useDHCP</option>
+        are enabled.
+      '';
+    };
+
     boot.initrd.network.postCommands = mkOption {
       default = "";
       type = types.lines;
@@ -91,7 +103,7 @@ in
 
           # Acquire a DHCP lease.
           echo "acquiring IP address via DHCP..."
-          udhcpc --quit --now --script ${udhcpcScript} && hasNetwork=1
+          udhcpc --quit --now --script ${udhcpcScript} ${udhcpcArgs} && hasNetwork=1
         fi
       ''
 

nixos/modules/system/boot/luksroot.nix

@@ -5,7 +5,7 @@ with lib;
 let
   luks = config.boot.initrd.luks;
 
-  openCommand = name': { name, device, header, keyFile, keyFileSize, allowDiscards, yubikey, ... }: assert name' == name; ''
+  openCommand = name': { name, device, header, keyFile, keyFileSize, allowDiscards, yubikey, fallbackToPassword, ... }: assert name' == name; ''
 
     # Wait for a target (e.g. device, keyFile, header, ...) to appear.
     wait_target() {
@@ -43,8 +43,17 @@ let
     open_normally() {
         echo luksOpen ${device} ${name} ${optionalString allowDiscards "--allow-discards"} \
           ${optionalString (header != null) "--header=${header}"} \
-          ${optionalString (keyFile != null) "--key-file=${keyFile} ${optionalString (keyFileSize != null) "--keyfile-size=${toString keyFileSize}"}"} \
           > /.luksopen_args
+        ${optionalString (keyFile != null) ''
+        ${optionalString fallbackToPassword "if [ -e ${keyFile} ]; then"}
+            echo " --key-file=${keyFile} ${optionalString (keyFileSize != null) "--keyfile-size=${toString keyFileSize}"}" \
+              >> /.luksopen_args
+        ${optionalString fallbackToPassword ''
+        else
+            echo "keyfile ${keyFile} not found -- fallback to interactive unlocking"
+        fi
+        ''}
+        ''}
         cryptsetup-askpass
         rm /.luksopen_args
     }
@@ -324,6 +333,16 @@ in
             '';
           };
 
+          fallbackToPassword = mkOption {
+            default = false;
+            type = types.bool;
+            description = ''
+              Whether to fallback to interactive passphrase prompt if the keyfile
+              cannot be found. This will prevent unattended boot should the keyfile
+              go missing.
+            '';
+          };
+
           yubikey = mkOption {
             default = null;
             description = ''

nixos/modules/system/boot/modprobe.nix

@@ -54,7 +54,7 @@ with lib;
 
     environment.systemPackages = [ pkgs.kmod ];
 
-    system.activationScripts.modprobe =
+    system.activationScripts.modprobe = stringAfter ["specialfs"]
       ''
         # Allow the kernel to find our wrapped modprobe (which searches
         # in the right location in the Nix store for kernel modules).

nixos/modules/system/boot/networkd.nix

@@ -650,11 +650,7 @@ let
   unitFiles = map (name: {
     target = "systemd/network/${name}";
     source = "${cfg.units.${name}.unit}/${name}";
-  }) (attrNames cfg.units) ++
-  (map (entry: {
-    target = "systemd/network/${entry}";
-    source = "${config.systemd.package}/lib/systemd/network/${entry}";
-  }) (attrNames (builtins.readDir "${config.systemd.package}/lib/systemd/network")));
+  }) (attrNames cfg.units);
 in
 
 {

nixos/modules/system/boot/stage-2-init.sh

@@ -82,7 +82,6 @@ ln -s /proc/mounts /etc/mtab
 mkdir -m 01777 -p /tmp
 mkdir -m 0755 -p /var/{log,lib,db} /nix/var /etc/nixos/ \
     /run/lock /home /bin # for the /bin/sh symlink
-install -m 0700 -d /root
 
 
 # Miscellaneous boot time cleanup.