Does git return specific return error codes?

Question

Like merging errors, or rebase errors. Does it have a unique error code?

Answer 1

In short, no. You're going to see exit code 1 for errors, and 0 for success.

From a quick grepping of the source, there are some of the expected 127 and 128 for their specific purposes (command not found, errors already reported), and a few unusual codes in a few places, but for run of the mill errors, it's all exit(1).