* Partially revert r25991 because it depends on the x-updates branch.

svn path=/nixos/trunk/; revision=25995

modules/system/boot/stage-1.nix

@@ -245,6 +245,21 @@ let
             --replace 'ENV{DM_SBIN_PATH}="/sbin"' 'ENV{DM_SBIN_PATH}="${extraUtils}/bin"' \
             --replace /sbin/mdadm ${extraUtils}/bin/mdadm
       done
+
+      # !!! Remove this after merging the x-updates branch:
+
+      # Work around a bug in QEMU, which doesn't implement the "READ
+      # DISC INFORMATION" SCSI command:
+      #   https://bugzilla.redhat.com/show_bug.cgi?id=609049
+      # As a result, `cdrom_id' doesn't print
+      # ID_CDROM_MEDIA_TRACK_COUNT_DATA, which in turn prevents the
+      # /dev/disk/by-label symlinks from being created.  We need these
+      # in the NixOS installation CD, so use ID_CDROM_MEDIA in the
+      # corresponding udev rules for now.  This was the behaviour in
+      # udev <= 154.  See also
+      #   http://www.spinics.net/lists/hotplug/msg03935.html
+      substituteInPlace $out/60-persistent-storage.rules \
+        --replace ID_CDROM_MEDIA_TRACK_COUNT_DATA ID_CDROM_MEDIA
     ''; # */
   };