I've upgraded my mysql install from v5.7 to v8, and had gnorm not working anymore.
After some debug, I've found that this is due to the version of the mysql driver being a bit too old.
So I've tried upgrading all the dependencies in my fork and this worked.
I first removed the Gopkg files, the vendor folder, and made all the imports point to my fork, then dep init, tweaked the Gopkg.toml to set all the dependencies (but 1) on their master branch, then dep ensure -v -update, and voila, a working gnorm version with up-to-date dependencies.