Redmine

The problem is with changes.changeset_id, not changeset.id, that's a big difference :-) The id attribute in the changeset table is autoincremented by the DB, i.e. it gets set when committed to the DB. That id should then make its way to the Changes object rails tries to commit so that changes.changeset_id is populated, which obviously doesn't happen. Can you see if your DB holds a Changeset with an scmid of 7eab6ad7c6c3 or a revision of 647?

Have you done anything with either the redmine or the DB before this changeset should have been loaded?

Indeed, there's already an entry in changesets database with revision 647 and scmid 7eab6ad7c6c3 and is exactly the same as the one redmine try to fill.

Should I remove the entry in the database?

Are the other attributes the exact same as what you have posted above (minus the id)? If yes, there was a glitch and you should be able to delete it, if not, there is something wrong with the hg adapter recognizing two different commits as one.

It's the same value except the user_id. In the database, the user_id is 5 and in the redmine, it's nil.

Mmmh… To be honest, I don't know that portion of code good enough to give you a definitive answer. You can try on at your own risk to remove said database entry and to run the import again. The worst thing that I can imagine could happen is corruption in that part of the DB, but as it is "just" a cache of "metadata" about your repo, you could still delete the repository config in the project and import in again.

I removed the entry in the db, restart the process and now it works prefectly!

Thank you Felix for your help!

Well, glad it worked out well, though that still seems like a glitch, I don't have the time to investigate it more sadly.