The zlib repository's master branch had non-upstream changes pushed to
it by accident. Non baserock or personal branches should not be altered
as lorry will update them and it is considered an error if lorry cannot
To fix this the original master branch has been deleted, then replaced
with a new one, without the non-upstream changes.
When you next fetch from zlib you will get a message about a forced
update of master, this is normal, but it may leave your local branch
ahead. A 'git push' without any options will push those changes again,
so please synchronize your local branch if you need it.
You can do this by deleting your local branch with 'git branch -D
master' then if you need it for further development 'git checkout
Alternatively you should be able to reset the branch back to the same
point. If you use 'git status' or 'git branch -vv' it should say how
many commits ahead of upstream your local branch is. In my case it was
13. You can reset back these changes by 'git checkout master && git
reset --hard HEAD~13'