The Mercurial community has relied a bit too long on Bitbucket (by Atlassian) to provide “free” hosting for it. The ultimate purpose of such big corporations is to maximize profits and return of investments, while the needs of customers are of little concern, and marketing fills this semantic gap. Who did not know this triviality in advance, and merely ignored it on the spot when creating repositories on Bitbucket?
So the discontinuation of Mercurial by Bitbucket will happen in two stages, on 01-Feb-2020 and 01-Jun-2020. Independently of such market-driven policies, Mercurial developers are quite alive and active to develop alternatives. In the past few months, two emerging projects for (self)hosting of Mercurial repositories have gained some attention:
- Sourcehut as a newcomer for Git and Mercurial hosting
- Heptapod as a version of Gitlab for Mercurial (eventually both for Git and Mercurial). See also the blog for ongoing activity.
Development of these projects is very active, but they are not yet ready for production use.
In contrast, Phabricator is a pretty stable and scalable hosting platform right now; it supports Git, Mercurial, Subversion. In fact, Phabricator is a sophisticated platform for software project management, and repository hosting is only a secondary function of it. See also the related post on Isabelle/Phabrictor tooling, with Isabelle development as a notable example.
Update 21-Mar-2020: link to Heptapod blog.