This project is deprecated, as xFitter now supports an official docker container. You can pull this from: gitlab-registry.cern.ch/fitters/xfitter:master. If there is some need for using an older version of xFitter you can pull the code from this project using tags or branches, but I expect the URLs to change and do not plan to maintain this project.
See the docker documentation at: https://gitlab.cern.ch/fitters/xfitter/-/wikis/Docker
The full documentation is at: https://gitlab.cern.ch/fitters/xfitter/-/wikis/home
The source code for xfitter is at: https://gitlab.cern.ch/fitters/xfitter