support for git-annex as the filesystem
It would be good if Cromwell could support git-annex ( https://git-annex.branchable.com/ ) as a filesystem option. You'd specify files not by pathname but by checksum of their contents, e.g.
git-annex keeps track of where each file is stored, and has commands to fetch the file by checksum and to push files to configured destinations (cloud or local). It can be used to version analysis code and data together in a consistent way ( http://datalad.org ).