The primary git repository has been moved from www.swi-prolog.org to github.com. That means that developers need to push to the github repository. The repos at www.swi-prolog.org are synchronized three times per day. What does this mean?

Update an existing working tree to GitHub

Use the commands below to update a working tree for the development branch. Use swipl.git for the stable series. If you have a GitHub account and setup ssh, you can also use github@github.com:SWI-Prolog/swipl-devel.git.

% git remote set-url origin https://github.com/SWI-Prolog/swipl-devel.git
% git submodule sync

Checkout old versions

The submodule locations have changed on April 22, 2014. If you want to check out an older version, use the repositories at www.swi-prolog.org. You can use the above commands to switch freely between both sources or use git remote add to add both of them.