I've got a repoA with 2 lfs tracked files. I'm bringing that repo into repoB like this

cd repoB
git fetch repoA somebranch
git checkout -b temp FETCH_HEAD
git rebase someotherbranch

note there is no common history between the 2 repos and should be no file conflicts either.
Anyway, this prints several lines of "Applying: ..." and then

Using index info to reconstruct a base tree...
Falling back to patching base and 3-way merge...
error: Your local changes to the following files would be overwritten by merge:
    Assets/HappyFunTimes/HappyFunTimesCore/Server/Resources/HFTOSXServer.bytes
Please, commit your changes or stash them before you can merge.
Aborting
error: Failed to merge in the changes.
Patch failed at 0340 update server
The copy of the patch that failed is found in: .git/rebase-apply/patch

When you have resolved this problem, run "git rebase --continue".
If you prefer to skip this patch, run "git rebase --skip" instead.
To check out the original branch and stop rebasing, run "git rebase --abort".

How do I fix this?

git status showed this

$ git status
rebase in progress; onto 5af1f30
You are currently rebasing branch 'gamepad' on '5af1f30'.
  (all conflicts fixed: run "git rebase --continue")

Changes not staged for commit:
  (use "git add/rm <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

    modified:   Assets/HappyFunTimes/HappyFunTimesCore/Server/Resources/HFTOSXServer.bytes
    deleted:    Assets/HappyFunTimes/HappyFunTimesCore/Server/Resources/HFTOSXServer.sha256.bytes

no changes added to commit (use "git add" and/or "git commit -a")

Note: I tried just adding and committing the 2 files (voodoo) and then git rebase --continue which kept going until the next time the file was modified in the history at which point it got a similar error. I did the same thing and it finally finished. But then when I tried to rebase that onto another branch I got

Downloading Assets/HappyFunTimes/HappyFunTimesCore/Server/Resources/HFTOSXServer.bytes (7.48 MB)
Error downloading object: Assets/HappyFunTimes/HappyFunTimesCore/Server/Resources/HFTOSXServer.bytes (4743b094eeab821140773213ebabdaa81c9ac2eb1be1108e70e8d51ae52873dd)

Errors logged to /Users/gregg/src/hft-unity3d/.git/lfs/objects/logs/20160603T213456.110362284.log
Use `git lfs logs last` to view the log.
error: external filter git-lfs smudge -- %f failed 2
error: external filter git-lfs smudge -- %f failed
fatal: Assets/HappyFunTimes/HappyFunTimesCore/Server/Resources/HFTOSXServer.bytes: smudge filter lfs failed
Could not apply dc378b5d715103e9af0ee805ff2a3be1159739aa... add lfs support

Which kind of suggests I have no clue how to use git lfs correctly.

Is this supposed to work? Did miss a step? Should I have done something in repoB before rebasing? repoB is on the same machine but had no lfs files in it (no .gitattributes). that file doesn't appear until well into the history of repoA (where a large binary file was first needed).