This is a thread to ask, talk, and assist in mirroring filterlists and similar things.
From my first-hand experience:
GitHub → GitLab: Go to https://gitlab.com/projects/new while logged in → CI/CD for external repo → Connect repositories from GitHub. From that point on you can finetune the conversion process in various ways.
Important note: All commits in such a mirrored repo will have to be done on GitHub. Trying to commit on GitLab, will cause the GitLab branch to diverge from the GitHub branch and cause mirroring auto-commits from GitHub to GitLab to fail. Should this occur, the solution that I used was to remove the branch protection in the GitLab repo settings.
GitHub/GitLab/Git → Repo.or.cz: Go to https://repo.or.cz/regproj.cgi and fill in the needed details. The “admin password” is handled on a per-repo basis. The project name does not need to be the same as the original repo’s name. Ensure that “Hosting mode” is set to “Mirror mode”. It is in fact possible to mirror other people’s repos as well on that site.
Important note: The answer to the control question on the bottom is in fact “The sun”. I remember having a critical brain error the first time I used that site by answering “Alpha Centauri” over and over for half an hour…
GitHub → NotABug.org: NOT RECOMMENDED, due to a long-lasting bug that can lead to permanent 500 errors for all mirrored repos and which makes your NotABug account undeletable. Example 1, example 2, example 3, example 4. Such is the consistency and duration of the bug that I don’t even want to write a guide for this. In fact I mostly decided to create this thread in order to warn others against using that site.
If anyone else know about (or have maybe even tried out) other from-and-to combinations of list mirroring possibilities, then this is the thread to do so in.