git clone git@github.com:YOUR-USERNAME/YOUR-FORKED-REPO.git
cd into/cloned/fork-repo
git remote add upstream git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git
git fetch upstream
# Assume we are in your home directory | |
cd ~/ | |
# Clone the repo from GitLab using the `--mirror` option | |
$ git clone --mirror git@your-gitlab-site.com:mario/my-repo.git | |
# Change into newly created repo directory | |
$ cd ~/my-repo.git | |
# Push to GitHub using the `--mirror` option. The `--no-verify` option skips any hooks. |