+[[forcing-push]]
+What to do when a push fails
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If a push would not result in a <<fast-forwards,fast forward>> of the
+remote branch, then it will fail with an error like:
+
+-------------------------------------------------
+error: remote 'refs/heads/master' is not an ancestor of
+ local 'refs/heads/master'.
+ Maybe you are not up-to-date and need to pull first?
+error: failed to push to 'ssh://yourserver.com/~you/proj.git'
+-------------------------------------------------
+
+This can happen, for example, if you:
+
+ - use `git reset --hard` to remove already-published commits, or
+ - use `git commit --amend` to replace already-published commits
+ (as in <<fixing-a-mistake-by-editing-history>>), or
+ - use `git rebase` to rebase any already-published commits (as
+ in <<using-git-rebase>>).
+
+You may force git-push to perform the update anyway by preceding the
+branch name with a plus sign:
+
+-------------------------------------------------
+$ git push ssh://yourserver.com/~you/proj.git +master
+-------------------------------------------------
+
+Normally whenever a branch head in a public repository is modified, it
+is modified to point to a descendent of the commit that it pointed to
+before. By forcing a push in this situation, you break that convention.
+(See <<problems-with-rewriting-history>>.)
+
+Nevertheless, this is a common practice for people that need a simple
+way to publish a work-in-progress patch series, and it is an acceptable
+compromise as long as you warn other developers that this is how you
+intend to manage the branch.
+
+It's also possible for a push to fail in this way when other people have
+the right to push to the same repository. In that case, the correct
+solution is to retry the push after first updating your work by either a
+pull or a fetch followed by a rebase; see the
+<<setting-up-a-shared-repository,next section>> and
+link:cvs-migration.html[git for CVS users] for more.
+