News and Updates

SQLAlchemy Migrated to Git

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The SQLAlchemy source repository has been migrated to Git.

There are now twin repository mirrors for SQLAlchemy hosted at Bitbucket and Github.

Rationale for the migration includes the following:

  • Git manages the size of the repository more efficiently; while the Mercurial repository has been approaching 50M in size, the Git repository is only 17M.
  • Git allows for lightweight, temporary feature branches which can be freely renamed or deleted, including that dead branches can be pruned of their changesets. The Mercurial repository had filled up with several dozen development branches, some abandoned, which while they could be hidden via "close", could never be removed. While Mercurial supports part of Git's functionality via the "bookmarks" extension, users typically are unaware of this and continue to create unwieldy branches. Bookmarks don't solve the issue of removing unused changesets in any case. Feature branches in Mercurial typically had to proceed in separate clones to allow for the possibility of abandonment without clogging up the main repository.
  • While Mercurial has various extensions which emulate advanced Git features like "rebase" and "collapse", manipulation of history for the purposes of collapsing changesets or manipulating branches is a first class and widely used feature in Git.
  • Largely due to the popularity of Github, Git has achieved a much higher userbase, to the degree where we regularly have users requesting us to move to Git so they can provide pull requests (as they don't want to learn Mercurial).

SQLAlchemy's issue repository will remain hosted on Trac; while a Git repository can be mirrored in any number of places, an issue repository cannot (for now! Can someone please create a distributed issue tracker? Should be pretty doable, though getting Github/Bitbucket to use it, not so much...), so SQLAlchemy's long history of issue discussion remains maintained directly by the project.

While we are favoring Bitbucket as the location of the "primary" push repository, users who wish to contribute should feel free to provide pull requests from either Bitbucket or Github; we should be able to accommodate both.

The SQLAlchemy Mercurial repository at http://hg.sqlalchemy.org/ will remain up for some period of time until we observe that requests have fallen off - note that this repository is not being mirrored from Git, as the repository would need to be recreated with bookmarks instead of branches which require recreating the entire revision history.