The change looks good, but I'm not sure why the submodule got updated? Was it out of date?

I know nothing about submodules.

I can push a branch preserving your commits, but resolving the submodule issue. Otherwise, you could give this a shot:

# Ensure all the submodules are initialized and checked out at the current SHAs
git submodule update --init --recursive
(
  cd reppy/rep-cpp
  git pull --rebase origin master
  # Update the googletest submodule
  git submodule update --init --recursive
)

git add reppy
git commit --amend

And thanks for the PR, btw!

Hm, that left me with a repo that can't push -- not really worth debugging, though.