Based on what I see in the buildout.coredev docs it suggests that after altering checkouts.cfg you should push to the branch from which you checked out.
However if I follow that guide my .git/config only has an https:// url (not so convenient for pushes).
Is it standard to add a pushurl?
This is what my altered .git/config file looks like:
[core]
repositoryformatversion = 0
filemode = true
bare = false
logallrefupdates = true
[remote "origin"]
url = https://github.com/plone/buildout.coredev
fetch = +refs/heads/*:refs/remotes/origin/*
pushurl = git@github.com:plone/buildout.coredev.git
[branch "5.0"]
remote = origin
merge = refs/heads/5.0