Mailing Lists
Mailing Lists:
Three mailing lists are provided for people interested in Unison. It is strongly recommended that regular Unison users subscribe to one of the first two:
  • unison-announce is a moderated list where new Unison releases are announced. It is very low volume, averaging less than one message per month.

    To subscribe, you can either visit (you will be asked to create a Yahoo groups account if you do not already have one), or else send an email to (which will simply add you to the list, whether you have a Yahoo account or not).

  • unison-users is a higher-volume discussion forum for users of unison. It is used for discussions of many sorts --- proposals and designs for new features, installation and configuration questions, usage tips, etc. It is also moderated, but just to filter spam.

    To subscribe, you can either visit or else send an email to

    Release announcements are made on both of these lists, so there is no need to subscribe to both.

  • unison-hackers is for informal discussion among Unison developers. Anyone who considers themselves a Unison expert and wishes to lend a hand with maintaining and improving Unison is welcome to join. This list is also where commit logs are posted for the developer sources. Only members can post.

    To subscribe, you can either visit or else send an email to unison-hackers-subscribe at lists dot seas dot upenn dot edu.

Archives of all the lists are available (and publically visible) via the above links.

Reporting bugs:
If Unison is not working the way you expect, here are some steps to follow.
  • First, take a look at the Unison documentation, especially the FAQ section. Lots of questions are answered there.
  • Next, try running Unison with the "-debug all" command line option. This will cause Unison to generate a detailed trace of what it's doing, which may help pinpoint where the problem is occurring.
  • If this doesn't clarify matters, try sending an email describing your problem to the users list at (Make sure you subscribe first, so that you'll see people's responses in case they reply only to the list!) Please include the version of Unison you are using (unison -version), the kind of machine(s) you are running it on, a record of what gets printed when the "-debug all" option is included, and as much information as you can about what went wrong.
  • If you think you've discovered an actual bug in Unison, you can report it using the Github issue tracker.
Feature Requests:
Feel free to post feature requests, suggestions, etc. to