Why is Git rejecting my pull simply because I have a commit on my local branch?

Question

There is a Git repository on a server that my colleague and I both push to and pull from. It works fine as long as we pull before committing.

However, if he has pushed to the master branch, and in the mean time I have made a local commit, when I try to pull I get this:

! [rejected]        master    -> master  (non-fast-forward)

But I know that there should be no conflict.

The way I get around it is by pulling into a new temporary branch and then merging that into my master like this:

% git pull origin master:temp
From ssh://example.com/home/my/remote/repo
 * [new branch]      master    -> temp
Already up-to-date.
% git merge temp
Already up-to-date.
% git push origin master:master

Notice that Git acts like I'm not doing anything, but really I have shaken it into submission.

Recently I realized that instead of trying to to "convince" Git that it's OK for me to pull. I can just pretend that I haven't committed yet with git reset --soft HEAD^ and git stash and then do the pull and commit on top of that.

What might be causing this strangely finicky behavior?

I was able to reproduce this problem all on my local machine. Here's what I did:

First I made the first "local" repository and added a file.

% cd
% mkdir local-1
% cd local-1/
% mkdir website
% cd website/
% git init
Initialized empty Git repository in /Users/jason/local-1/website/.git/
% touch file
% git add .
% git commit -m 'added file'
[master (root-commit) 6d4b322] added file
 0 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 file

Then I made the "remote" repository.

% cd
% mkdir remote
% cd remote
% mkdir website.git
% cd website.git/
% git init --bare
Initialized empty Git repository in /Users/jason/remote/website.git/

Then I went back to the local, created a ref and pushed to the remote.

% cd ~/local-1/website/
% git remote add web ~/remote/website.git
% git push web +master:refs/heads/master
Counting objects: 3, done.
Writing objects: 100% (3/3), 207 bytes, done.
Total 3 (delta 0), reused 0 (delta 0)
Unpacking objects: 100% (3/3), done.
To /Users/jason/remote/website.git
 * [new branch]      master -> master

After that I cloned the remote into a second local.

% cd
% mkdir local-2
% cd local-2
% git clone ~/remote/website.git
Cloning into website...
done.

Then I created a ref to the remote from the second local and pushed (this is where I am creating the problem I think).

% cd website/
% git remote add web ~/remote/website.git
% git push web +master:refs/heads/master
Everything up-to-date

Then I made a change to local-2, committed, and pushed.

% touch another
% git add .
% git commit -m 'added another'
[master be91180] added another
 0 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 another
% git push web
Counting objects: 3, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (2/2), 238 bytes, done.
Total 2 (delta 0), reused 0 (delta 0)
Unpacking objects: 100% (2/2), done.
To /Users/jason/remote/website.git
   6d4b322..be91180  master -> master

Finally, I made a different change to local-1, committed, and tried to push.

% cd ~/local-1/website/
% touch something
% git add .
% git commit -m 'added something'
[master 3984529] added something
 0 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 something
% git push web
To /Users/jason/remote/website.git
 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to '/Users/jason/remote/website.git'
To prevent you from losing history, non-fast-forward updates were rejected
Merge the remote changes (e.g. 'git pull') before pushing again.  See the
'Note about fast-forwards' section of 'git push --help' for details.

Blast! How about a pull?

% git pull web master:master
From /Users/jason/remote/website
 ! [rejected]        master     -> master  (non-fast-forward)

OK, so there's the problem. How do I fix it?

Answer 1

You probably meant to do:

git pull web master

Using master:master is trying to directly update you local master branch in the fetch stage of the pull which is causing the non fast-forward error.

If you're on a branch that is set up to track web/master then you only need git pull web and this will update your remote tracking branches as well.