Why doesn't git allow me to safely delete a branch?

Question

I needed to merge two branches --

second

into

first

and then get rid of

second

. Here's what I did:

git clone
d the project to get a fresh copy

git checkout --track origin/second
, made some changes, and committed

git checkout --track origin/first
, made some changes, and committed

git merge second
(git says "merge made by recursive")

git branch -d second

Then git says:

$ git branch -d second

warning: not deleting branch 'second' that is not yet merged to

         'refs/remotes/origin/second', even though it is merged to HEAD.

error: The branch 'second' is not fully merged.

If you are sure you want to delete it, run 'git branch -D second'.

Why is this happening? I've never gotten this message after a merge before. The merge worked just fine, no conflicts. How do I safely delete the

second

branch?

Answer 1

Based on my experiments and @knittl's and @twalberg's comments, it seems that git just wanted me to push my changes to the second branch before deleting it.

I did:

$ git checkout second
$ git push origin second
$ git checkout first
$ git branch -d second

which worked without warnings.