Git: "Cannot 'squash' without a previous commit" error while rebase

I had a similar problem which I solved as follows:

This is the commit group I wanted to squash:

1 s 01cc5a08 Removes open div
2 s a2b6eecf Restores old fonts
3 s 603479ff Cleans left out div
4 pick 5afdbc33 Update: show logo on landing page
5 s 04c1cb13 change version of dev and prod from 1 to 2
6 s bbe6a8f8 Update: show logo on landing page if they have one
7 s c0d6008a Adds check for C users

As you can see, I wanted no. 4, but 1, 2 and 3 had no previous commit to squash into. Hence the Cannot 'squash' without a previous commit error.

My solution was to use the r option for # r, reword = use commit, but edit the commit message

So my commits list looked like this:

1 r 01cc5a08 Removes open div
2 s a2b6eecf Restores old fonts
3 s 603479ff Cleans left out div
4 s 5afdbc33 Update: show logo on landing page
5 s 04c1cb13 change version of dev and prod from 1 to 2
6 s bbe6a8f8 Update: show logo on landing page if they have one
7 s c0d6008a Adds check for C users

After saving, the interactive shell asked me for the rewording of the chosen commit.

After that, my commit log resulted in a single commit which resulted in a cleaner commit history.


I had this problem and the reason why it happened in my case was that, you cannot squash older commits onto a new commit. Here is an example say you have 3 commits:

1 pick 01mn9h78 The lastest commit
2 pick a2b6pcfr A commit before the latest
3 pick 093479uf An old commit i made a while back

Now if you say git rebase -i HEAD~3 and you do something like

1 pick 01mn9h78 The lastest commit
2 s a2b6pcfr A commit before the latest
3 s 093479uf An old commit i made a while back

This will result in the error:

error: cannot 'squash' without a previous commit You can fix this with 'git rebase --edit-todo' and then run 'git rebase --continue'. Or you can abort the rebase with 'git rebase --abort'.

Solution :

When squashing commits, you should squash recent commits to old ones not vice versa thus in the example it will be something like this:

1 s 01mn9h78 The lastest commit
2 s a2b6pcfr A commit before the latest
3 pick 093479uf An old commit i made a while back

This will work fine, incase you want all your commit messages, I would suggest fixup instead of squash.


Interactive rebase presents commits in the reverse order of what you are used to when using git log. git rebase -i replays the selected commits in the exact (top-down) order they are listed in the saved rebase instructions file. When squashing, the commit selected for squashing is combined with the commit that precedes it in the (edited) list, i.e. the commit from the previous line. In your case - there is no previous commit for 56bcce7. You have to do one of the following

  • git rebase -i HEAD~3 (if you want to squash 56bcce7 into 684f917)
  • If you mean to combine 56bcce7 with e43ceba, and e43ceba doesn't depend on 56bcce7, then simply reorder them:

    r e43ceba Lint.py: Replace deprecated link
    s 56bcce7 Closes #2774
    

    UPDATE: Gus's answer below suggests a better way of doing the same, without reordering the two commits:

    r 56bcce7 Closes #2774
    s e43ceba Lint.py: Replace deprecated link
    

    This will squash/merge the two commits into one. When the interactive rebase asks for a reworded commit message for 56bcce7, provide the commit message that describes the union of 56bcce7 and e43ceba.


Squash with the reverse logic. You'll be able to select the desired commit message at the later step.

  • pick the first commit that you don't want the commit-message for.
  • squash or fixup the commit(s) that you want to merge, until the one that has the commit message that you actually wanted.
pick 56bcce7 Closes #2774
squash e43ceba Lint.py: Replace deprecated link
  • confirm the change (:x)
  • delete the commit message(s) that you don't want and leave only the message from the commit that you desire (in this case: Lint.py: Replace deprecated link).
  • confirm the choice (:x)

Hope it's clearer for somebody ✌🏽

Tags:

Git

Rebase