build_image: silence the "No space left on device" message

build_image

 #!/bin/bash
 
 # Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Script to build a bootable keyfob-based chromeos system image from within
 # a chromiumos setup. This assumes that all needed packages have been built into
 # the given target's root with binary packages turned on. This script will
 # build the Chrome OS image using only pre-built binary packages.
@@ skipping 505 matching lines @@
     --usepkgonly --depclean ${EMERGE_JOBS}
 
   trap - EXIT
   ${SCRIPTS_DIR}/mount_gpt_image.sh -u -r "${ROOT_FS_DIR}" \
     -s "${STATEFUL_FS_DIR}" -e "${ESP_FS_DIR}"
 }
 
 zero_free_space() {
   local fs_mount_point=$1
   info "Zeroing freespace in ${fs_mount_point}"
-  sudo dd if=/dev/zero of="${fs_mount_point}/filler" oflag=sync bs=4096 || true
+  # dd is a silly thing and will produce a "No space left on device" message
+  # that cannot be turned off and is confusing to unsuspecting victims.
+  ( sudo dd if=/dev/zero of="${fs_mount_point}/filler" oflag=sync bs=4096 \
+    || true ) 2>&1 |grep -v "No space left on device"
   sudo rm -f "${fs_mount_point}/filler"
   sudo sync
 }
 
 create_base_image() {
   local image_name=$1
 
   trap "cleanup && delete_prompt" EXIT
 
   # Create and format the root file system.
@@ skipping 271 matching lines @@
   echo "Developer image created as ${DEVELOPER_IMAGE_NAME}"
 fi
 
 print_time_elapsed
 
 echo "To copy to USB keyfob, do something like:"
 echo "  ./image_to_usb.sh --from=${OUTSIDE_OUTPUT_DIR} --to=/dev/sdX"
 echo "To convert to VMWare image, INSIDE the chroot, do something like:"
 echo "  ./image_to_vm.sh --from=${OUTSIDE_OUTPUT_DIR} --board=${BOARD}"
 echo "from the scripts directory where you entered the chroot."