$ git rebase upstream/master
First, rewinding head to replay your work on top of it...
Using index info to reconstruct a base tree...
Falling back to patching base and 3-way merge...
CONFLICT (content): Merge conflict in conflicting_file_1.txt
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch' to see the failed patch
Patch failed at 0001 Commit #1
Resolve all conflicts manually, mark them as resolved with
"git add/rm <conflicted_files>", then run "git rebase --continue".
You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".