DCO Missing: How to fix

If you are reading this, then you want to contribute to one of Block's projects. That's awesome and we're glad you're here 👍.
However, this also means that you probably have not added the "signed-off-by" signature to one or more of your commits in the pull request.

Before we move on, please read what is the Developer Certificate of Origin (DCO).

You may now have a fair question: why does Block enforce the DCO? There are two key reasons:

1. By signing off the contribution, you are certifying it is either your intellectual property or a valid contribution given its respective open source license origin.
2. It follows that your contribution is, by default if valid, considered your intellectual property in countries such the United States.
   Thus you could ask the project maintainer to remove one (or more) of your contributions in the future.
   This may get very complicated as the project grows larger and becomes more well-known: imagine rewriting the Git history for everybody!

Thus, the DCO works as a sort of insurance against such cases.

This manual should help you to add the required Signed-off-by: Your Name <name@email.com> to your commits in the pull request.

How To Add Sign-Offs Retroactively

Fix Option 1: Amend Single Commit

If there is only a single commit in your pull request, adding the signature is as simple as:

git commit --amend --no-edit --signoff
git push -f origin feature/i18n-pt-BR

You can always squash several commits together; see: StackOverflow.

-s is a shortcut for --signoff - you can use it instead.

Fix Option 2: rebase

If there is more than one commit in your pull request and your git client is modern enough (2.13+), rebase the required number of commits with --signoff:

git rebase --signoff HEAD^

Write ^ as many times as there are commits in your pull request.
Then, force push:

git push -f origin feature/i18n-pt-BR

Fix Option 3: Interactive Rebase

If there is more than one commit in your pull request and your git is older than 2.13, you can do an interactive rebase with message editing:

git rebase -i HEAD^

Write ^ as many times as there are commits in your pull request.
A text will open; ensure that there are only your recent commits listed there.
Otherwise, exit the file and repeat the rebase command with the correct number of ^.

Now, mark all the commits with "reword" or "r". The rebase process will stop at each of your commits.

Execute as many times as you are asked to:

git commit --amend --no-edit --signoff
git rebase --continue

Then, force push:

git push -f origin feature/i18n-pt-BR

Fix Option 4: (Almost) Avoid Git

Git is sometimes frustrating, and you may want to keep distance from it sometimes for safety.
For now:

1. Copy the modified files to a backup directory;
2. Clone the repository again;
3. Overwrite the old file copies with the modified versions.

Then, execute:

git commit -a --signoff
git push -f origin feature/i18n-pt-BR

How To Prevent Missing Sign-offs In The Future?

Sign-off Option 1: Safe Plain-Vanilla

Always sign your commits by using the -s or --signoff flags when committing (e.g. git commit -s).

Sign-off Option 2: Repository-based Hooks

Alternatively, you may create a commit-msg hook in each given repository.
To do so, write in your local repository's .git/hooks/commit-msg the following:

#!/bin/sh
SIGNATURE="Signed-off-by: `git config --global --get user.name` <`git config --global --get user.email`>"
grep -qs "^${SIGNATURE}" "$1" || echo "\n${SIGNATURE}" >> "$1"

You need to do this for each repository independently.

If you want to create this hook automatically on every new git repository you will create from now on (using git init, git clone...) you can use git-templates; to do so, just save the script described above into (duplicate files):

• ~/.git-templates/hooks/prepare-commit-msg
• ~/.git-templates/hooks/commit-msg

And configure it globally:

git config --global init.templatedir ~/.git-templates

NOTE: You will still need to paste this hook in your existing git repositories.

Sign-off Option 3: Git Aliases

Git aliases are like "shortcuts" to more extensive commands and flags.

You can add the following lines (or as you see suit) to your ~/.gitconfig file:

[alias]
  cmsg = commit -s -m
  camend = commit -s --amend

You only need to do this once, and it will work whenever this ~/.gitconfig file is active.

this guide is based on src-d's DCO guide and is licensed under a CC-BY-SA-4.0 license