message: install_headers: skip externals that were unbundled
diff: @@ -628,6 +628,14 @@ genrule(
  continue
  fi
  + if [[ $${d} == external* ]]; then
  + extname="$${d#*external/}"
  + extname="$${extname%%/*}"
  + if [[ $${TF_SYSTEM_LIBS:-} == *$${extname}* ]]; then
  + continue
  + fi
  + fi
  +
  mkdir -p "$@/$${d}"
  cp "$${f}" "$@/$${d}/"
  done
  