Hi,
We were running gitlab package in debian stretch with some security patches backported. But we could not backport all security patches because some were very complex fixes.
Now we are on the latest security release. Most of the dependencies are available from stretch-backports but some are blocked by transitions.
You can install the new version from https://people.debian.org/~praveen/gitlab/
You can see the current status of getting gitlab 10.7.6 to official stretch-backports here https://salsa.debian.org/ruby-team/gitlab/wikis/stretch-backports
Thanks Praveen