Comments on: How to truncate git history (sample script included)

By: JT

JT — Mon, 29 Mar 2021 15:50:54 +0000

This works, but you will loose all timestamps for commits that are retained. Seems like the git team should address a real need to perform housekeeping for repos that undergo lots of change over many years.

By: Bogdan

Bogdan — Tue, 04 Aug 2015 15:58:34 +0000

Nigel,

I’ve just tested using git 2.4.6 – had no errors.
Check if this command has `master` at the end and completes successfully – looks like you are not switching to the `master` branch for some reason, which then prevents you from deleting the `temp` branch:

git rebase --onto temp $1 master

If you just ran all the code as a script – try issuing commands one by one, to see if there are any problems reported by the earlier commands.

By: Nigel Horne

Nigel Horne — Mon, 03 Aug 2015 20:03:16 +0000

It’s a great idea and just what I want, but it fails with this error:

error: Cannot delete the branch ‘temp’ which you are currently on.

By: Bogdan

Bogdan — Fri, 28 Mar 2014 09:57:05 +0000

@Cy – thanks, added both.

P.S. Nice email address!

By: cy

cy — Fri, 28 Mar 2014 06:31:30 +0000

Two things to add to that.

git prune --progress git gc --aggressive

the last might not be necessary. git prune will delete all the unreffed objects.

By: Bogdan

Bogdan — Tue, 31 Dec 2013 10:24:41 +0000

LaboDJ, I don’t see any differences to my code in the post…

P.S. I’ve also edited both my post and your comment to properly show double-dashes.

By: LaboDJ

LaboDJ — Mon, 30 Dec 2013 13:08:06 +0000

It works modified like so in latest git version:
#!/bin/bash git checkout --orphan temp $1 git commit -m 'Truncated history' git rebase --onto temp $1 master git branch -D temp

By: Tom

Tom — Fri, 07 Sep 2012 16:06:52 +0000

Based on notes at the bottom of “http://git-scm.com/docs/git-filter-branch”, I tried the technique in the original post above, then cloned into a new repo, then gc pruned, and then it was much smaller.

I haven’t tried the “graft then filter-branch then clone (and prune)” strategy. I presume it would give similar results?

I also haven’t tried the “destructive” reflog shrinking technique mention in the Git docs.

By: Mikael Lundin

Mikael Lundin — Sun, 12 Aug 2012 08:37:06 +0000

Thank you. This helped me a lot. I neeeded to truncate history to get rid of secrets I had stored in the code, as passwords and app keys, before pushing the whole repository to a public github repo.

By: Bogdan

Bogdan — Fri, 20 Jul 2012 15:21:28 +0000

If I remember it right, objects with no references to them are cleaned up during garbage collection (`git gc`); maybe there is a need to supply an extra option to gc (like `–prune`?).

By: Jimmy Soho

Jimmy Soho — Thu, 19 Jul 2012 10:51:07 +0000

This doesn't really truncate. It detaches all the commits up till refspec. But the commits remain present in the git tree. Any idea how to delete all the detached objects?

By: Sean Flanigan

Sean Flanigan — Fri, 04 May 2012 05:30:18 +0000

Thanks for the script!

Git 1.7.1 doesn’t support “checkout –orphan”, so I found I had to replace
git checkout –orphan temp $1
with
git checkout $1
git symbolic-ref HEAD refs/heads/temp

which may or may not be correct, but it /seems/ to work.