How to rebase the fork derived from another Git fork

Question

I am using following setup:

1. public repo is forked as repo1
2. repo2 is fork of repo1

Following commands don't work if I am trying to rebase the repo2:

git remote add upstream https://github.com/laanwj/etna_viv.git
git fetch upstream
git rebase upstream/master

The last command gives following error:

9$ git rebase upstream/master fatal: Needed a single revision invalid upstream upstream/master

Answer 1

That happens when the branch onto which you are rebasing has no commit (nothing was fetched from upstream/master), as seen here.

Make sure first that, once fetched upstream/master does exist, with at least one commit.