So, further investigation shows that the ansible 2.1 git module is just
broken here. ;)
I added a reproducer to:
https://github.com/ansible/ansible-modules-core/issues/1509
basically it shows changed all the time, even when it should not.
There's a hacky workaround there:
register: git_result
changed_when: "git_result.after|default('after') !=
git_result.before|default('before')"
Of course this needs fixing, but even so, the underlying question still
remains (because even after this is fixed, it will show changes when
there are changes in the git repos unless we pin to a SHA1).
kevin