HGitaly1: Hg SHAs
The bare minimum for HGitaly to be integrated in GitLab so that the SHAs seen by other components are the Mercurial Node IDs instead of Git commit ids.
In the Rails application, we have a new "Mercurial native" project type, that can be selected by users upon project creation.
Those Mercurial native repositories still undergo systematic conversion to Git at this point, and it's used only for a limited set of features.
This can be used in production with caution by early adopters.
There is no conversion facility for existing Mercurial projects