error: unable to create symlink ... (File name too long)

git rebase -i 'abcdef123^'

git show

git commit --amend
git rebase --continue

git clone --no-checkout the-repo tmp-clone-dir
cd tmp-clone-dir
git config core.symlinks false
git checkout
cp the-problem-file the-problem-file.bak # make a backup
git rm the-problem-file
git commit -m 'Removed problem file pretending to be a symlink' the-problem-file
mv the-problem-file.bak the-problem-file # restore the backup; now it will be of type file
git commit -m 'Added back the problem file - now with the correct type' the-problem-file
git push origin master
cd ..
rm -rf tmp-clone-dir  # IMPORTANT

git config core.symlinks false
git rm <problem-file>
git commit <problem-file>
git push
git config core.symlinks true