Automating versioning for WWW.LoadFromCacheOrDownload

I have a large amount of content that is broken into small asset bundles, which works fine. When I create the asset bundles, I’d like to determine whether any of the assets in that bundle have changed, which I could then use to determine whether to update the version number for that bundle.

My question is how can I tell that an asset bundle has changed? I’ve tried direct file comparisons, but BuildPipeline.BuildAssetBundle() doesn’t seem to make the same file even when run on the exact same assets.

I use the BuildAssetBundleOptions.DeterministicAssetBundle option for BuildPipeline.BuildAssetBundle() and then I do get exactly the same file, so hashing works as a comparator.