src/server/pfs/server/driver.go
func (d *driver) scratchCommitPrefix(commit *pfs.Commit) string {
	// TODO(msteffen) this doesn't currenty (2018-2-4) use d.scratchPrefix(),
	// but probably should? If this is changed, filepathFromEtcdPath will also
	// need to change.
	return path.Join(commit.Repo.Name, commit.ID)
}
func (d *driver) scratchCommitPrefix(commit *pfs.Commit) string {
	// TODO(msteffen) this doesn't currenty (2018-2-4) use d.scratchPrefix(),
	// but probably should? If this is changed, filepathFromEtcdPath will also
	// need to change.
	return path.Join(commit.Repo.Name, commit.ID)
}
// scratchCommitPrefix returns an etcd prefix that's used to temporarily
// store the state of a file in an open commit.  Once the commit is finished,
// the scratch space is removed.