Jujutsu and Git [LWN.net]

Jujutsu and Git

Posted Feb 13, 2026 22:42 UTC (Fri) by sunshowers (guest, #170655)
In reply to: Jujutsu and Git by jc2026
Parent article: Evolving Git for the next decade

> But now I realize that was just a surface-level, naive analysis.

The lack of universal undo in Git is not a surface-level analysis. It is a fundamental limitation in essentially every pre-jj VCS. (No. the reflog is not universal undo.)

Having universal undo like in jj completely changes your level of confidence with source control operations. Screw up somehow? Make a bad edit? Simply run jj undo. People become experts much quicker when they can make mistakes and easily undo them.

Based on jj's experience I've started building an operation log and universal undo into basically any project where it's a good fit.

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Jujutsu and Git

Posted Feb 14, 2026 4:28 UTC (Sat) by jc2026 (subscriber, #182142) [Link]

The "universal undo" of jj is achieved by removing some state concepts from git. That may be an improvement in some people's eyes but it makes certain commit history manipulations and constructions more difficult. I'm not the only person to think this. https://github.com/jj-vcs/jj/discussions/1905 I think git was built the way it is, as opposed to the way jj is, to solve a particular problem.

>Based on jj's experience I've started building an operation log and universal undo into basically any project where it's a good fit.

jj did not invent the concept of undo or anything. Different tools have different levels of sophistication in their staging and undo features. Vim for example has an undo tree. SQL databases have transactions. Git has the reflog and the ability to search and go back to any recent commit, tagged or not, and start over (outside of some bizarre circumstances that you must explicitly walk into).