build_image: rename dev-only-extras.tbz2

The tbz2 suffix makes portage unhappy and spams a lot of warnings
that in turn makes users unhappy.  Rename to a file portage won't
care about and use better compression in the process.

It's safe to rename as the build will skip a missing file atm.

TEST=CQ passes

Change-Id: I49e6b48fabd3762703f4eecb2fd0d5df14407063
Tested-by: Mike Frysinger <>
Reviewed-by: Michael Mortensen <>
Commit-Queue: Mike Frysinger <>
diff --git a/build_library/ b/build_library/
index 0f25608..d506718 100755
--- a/build_library/
+++ b/build_library/
@@ -473,10 +473,8 @@
     # stateful since we created a symlink for those. We ignore the
     # symlink in this package since the directory /usr/local/var
     # exists in the target image when dev_install runs.
-    # TODO(deymo): Move dev-only-extras.tbz2 outside packages. See
-    # for details.
-    sudo tar -cf "${BOARD_ROOT}/packages/dev-only-extras.tbz2" -I pbzip2 \
-      --exclude=var -C "${root_fs_dir}/usr/local" .
+    sudo tar -cf "${BOARD_ROOT}/packages/dev-only-extras.tar.xz" \
+      -I 'xz -9 -T0' --exclude=var -C "${root_fs_dir}/usr/local" .
     create_dev_install_lists "${root_fs_dir}"