E-mail privacy in GitHub

Oct 2023

Future commits

Check both Keep e-mail private and Block command-line pushes options in your GitHub e-mail settings.
Set your GitHub private e-mail address globally of per-project:

# current project
$ git config user.email "12345678+username@users.noreply.github.com"

# global
$ git config --global user.email "12345678+username@users.noreply.github.com"

Past commits

WARNING: These steps rewrite your repository history. Read about collaboration and rewriting history.

Last commit

$ git commit --amend --no-edit \
    --author="$(git config user.name) <$(git config user.email)>"

Bulk edition

Install git-filter-repo which is the official git filter-branch replacement.
Clone repo (bare or not)

$ git clone --bare https://hostname/user/repo.git
$ cd repo.git

Update e-mail and/or name from all commits matching your old@email.com using the mailmap mechanism:

# This file follows gitmailmap format: https://git-scm.com/docs/gitmailmap
$ cat >/tmp/mailmap <<EOF
<12345678+username@users.noreply.github.com> <old@email.com>
EOF

$ git filter-repo --mailmap /tmp/mailmap

# Alternative: Create .mailmap and then --use-mailmap

Verify author information has been correctly updated:

$ git log --all --format='%ae%n%ce' | sort -u

Re-add remote repository (git-filter-repo deletes remotes as a safety measure to avoid unintended history rewrites!)

$ git remote add origin <remote-url>

Force push changes (!)

$ git push --force --branches --tags --prune origin

References