hide_output() {
  { set +x; } 2>/dev/null
  on_err="
echo ERROR: An error was encountered with the build.
cat /tmp/build.log
exit 1
"
  trap "$on_err" ERR
  bash -c "while true; do sleep 30; echo \$(date) - building ...; done" &
  PING_LOOP_PID=$!
  "$@" &> /tmp/build.log
  trap - ERR
  kill $PING_LOOP_PID
  set -x
}

# Copied from ../../shared.sh
function retry {
  echo "Attempting with retry:" "$@"
  local n=1
  local max=5
  while true; do
    "$@" && break || {
      if [[ $n -lt $max ]]; then
        sleep $n  # don't retry immediately
        ((n++))
        echo "Command failed. Attempt $n/$max:"
      else
        echo "The command has failed after $n attempts."
        return 1
      fi
    }
  done
}

# Copied from ../../init_repo.sh
function fetch_github_commit_archive {
    local module=$1
    local cached="download-${module//\//-}.tar.gz"
    retry sh -c "rm -f $cached && \
        curl -f -sSL -o $cached $2"
    mkdir $module
    touch "$module/.git"
    tar -C $module --strip-components=1 -xf $cached
    rm $cached
}