Bitbucket is removing mercurial support along with all mercurial repositories.
I decided to move the source code to sourcehut.
Here is the mercurial repository: https://hg.sr.ht/~hyozd/serialplot/
Here is the new issue tracker: https://todo.sr.ht/~hyozd/serialplot
I haven't moved download files yet. I will probably have to host them myself. Sourcehut doesn't provide file hosting.