if [ ! -d "${INSTALL_ROOT}/usr/src/linux/tools/perf" ]; then
  message "\n${PROBLEM_COLOR}ERROR: Linux kernel sources under ${FILE_COLOR}${INSTALL_ROOT}/usr/src/linux${PROBLEM_COLOR} are required"
  message "to build this spell, either install the ${SPELL_COLOR}linux${PROBLEM_COLOR} spell or unpack"
  message "kernel sources matching your running kernel manually.${DEFAULT_COLOR}\n"

  return 1
fi
