Retry on build_image failures and make sbt more aggressive by default

src/scripts/sync_build_test.sh

 #!/bin/bash
 
 # Copyright (c) 2010 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 sync your checkout, build a Chromium OS image, and test it all
 # with one command.  Can also check out a new Chromium OS checkout and
 # perform a subset of the above operations.
 #
@@ skipping 45 matching lines @@
     "Use this as the chronos user passwd (defaults to \$CHRONOS_PASSWD)"
 DEFINE_string chroot "" "Chroot to build/use"
 DEFINE_boolean force_make_chroot ${FLAGS_FALSE} "Run make_chroot indep of sync"
 DEFINE_string grab_buildbot "" \
     "Instead of building, grab this full image.zip URI generated by the \
 buildbot"
 DEFINE_boolean image_to_live ${FLAGS_FALSE} \
     "Put the resulting image on live instance (requires --remote)"
 DEFINE_string image_to_usb "" \
     "Treat this device as USB and put the image on it after build"
-# You can set jobs > 1 but then your build may break and you may need
-# to retry.  Setting it to 1 is best for non-interactive sessions.
 DEFINE_boolean interactive ${FLAGS_FALSE} \
     "Tell user what we plan to do and wait for input to proceed" i
 DEFINE_integer jobs -1 "Concurrent build jobs"
 DEFINE_boolean master ${FLAGS_TRUE} "Master an image from built code"
 DEFINE_boolean mod_image_for_test ${FLAGS_FALSE} "Modify the image for testing"
 DEFINE_string remote "" \
     "Use this hostname/IP for live updating and running tests"
 DEFINE_string repo "${CHROMIUMOS_REPO}" "gclient repo for chromiumos"
 DEFINE_boolean sync ${FLAGS_TRUE} "Sync the checkout"
 DEFINE_string test "" \
@@ skipping 114 matching lines @@
     if [[ -z "${device}" ]]; then
       echo "Expected --image_to_usb option of /dev/* format"
       exit 1
     fi
     local is_removable=$(cat /sys/block/${device}/removable)
     if [[ "${is_removable}" != "1" ]]; then
       echo "Could not verify that ${device} for image_to_usb is removable"
       exit 1
     fi
   fi
+  
+  if [[ ${FLAGS_jobs} -eq -1 ]]; then
+    FLAGS_jobs=$(cat /proc/cpuinfo | grep -c processor)
+  fi
 }
 
 
+function describe_jobs() {
+  local jobs=" single job (slow but no retries)"
+  if [[ ${FLAGS_jobs} -gt 1 ]]; then
+    jobs=" ${FLAGS_jobs} jobs"
+  fi
+  echo ${jobs}
+}
+
 # Prints a description of what we are doing or did
 function describe_steps() {
   if [[ ${FLAGS_sync} -eq ${FLAGS_TRUE} ]]; then
     echo " * Sync client (gclient sync)"
     if is_google_environment; then
       echo " * Create proper src/scripts/.chromeos_dev"
     fi
   fi
   if [[ ${FLAGS_force_make_chroot} -eq ${FLAGS_TRUE} ]]; then
     echo " * Rebuild chroot (make_chroot) in ${FLAGS_chroot}"
   fi
   local set_passwd=${FLAGS_FALSE}
   if [[ ${FLAGS_build} -eq ${FLAGS_TRUE} ]]; then
     local withdev=""
-    local jobs=" single job (slow but safe)"
-    if [[ ${FLAGS_jobs} -gt 1 ]]; then
-      jobs=" ${FLAGS_jobs} jobs (may cause build failure)"
-    fi
+    local jobs=$(describe_jobs)
     if [[ ${FLAGS_withdev} -eq ${FLAGS_TRUE} ]]; then
       withdev=" with dev packages"
     fi
-    echo " * Build image${withdev}${jobs}"
+    echo " * Build image${withdev} with ${jobs}"
     set_passwd=${FLAGS_TRUE}
     if [[ ${FLAGS_build_autotest} -eq ${FLAGS_TRUE} ]]; then
       echo " * Cross-build autotest client tests (build_autotest)"
     fi
   fi
   if [[ ${FLAGS_master} -eq ${FLAGS_TRUE} ]]; then
-    echo " * Master image (build_image)"
+    local jobs=$(describe_jobs)
+    echo " * Master image (build_image) with ${jobs}"
   fi
   if [[ -n "${FLAGS_grab_buildbot}" ]]; then
     if [[ "${FLAGS_grab_buildbot}" == "LATEST" ]]; then
       echo " * Grab latest buildbot image under ${FLAGS_buildbot_uri}"
     else
       echo " * Grab buildbot image zip at URI ${FLAGS_grab_buildbot}"
     fi
   fi
   if [[ ${FLAGS_mod_image_for_test} -eq ${FLAGS_TRUE} ]]; then
     if [[ -n "${FLAGS_grab_buildbot}" ]]; then
@@ skipping 340 matching lines @@
   fi
 
   trap - EXIT
   echo "Successfully used ${FLAGS_top} to:"
   describe_steps
   show_duration
 }
 
 
 main $@