how to total offline build between different machine and maintain a cache repo?

[williamlin0518]

I currently want to build LiteRT in offline mode and upload these cache to let another computer use these dependency to offline build:

my workflow is:

1. run bazel --output_base cache fetch //... to fetch all external dependency locally at cache on machine 1, which has access to the internet.

2. then test locally build target without internet, it works
   bazel --output_base cache //path/to/target

3. upload these cache folder to machine 2 to offline build
   but this step got failed, and it seems to delete dependency repo in cache/external and re fetch again, so cause error