Rebuilding while `git rebase` fails

[BenBE]

When trying to configure the project while performing a git rebase operation, the cmake .. step fails.

Steps to reproduce:

git rebase -x 'bash -c "mkdir -p build && cmake .. && make"` HEAD~

Expected result: Simply rebuilds the project for all commits

Actual result: Configuration crashes due to internal git environment causing the abseil stuff trying to clone into the parent repository (which just performs the rebase).

Background: Running the above command is usually a quick way to check all intermediate commits to build properly (in a somewhat automated manner).