cd nodebb (or path to where nodebb is installed)
git checkout v1.12.x
git merge origin/v1.12.x
I have a "one liner" that I use like this. This is what I do...git fetch && git checkout v1.12.x && git pull && ./nodebb stop && npm i && ./nodebb upgrade && npm i && ./nodebb start && ./nodebb log
I put the version right at the beginning so there is just one place to change it (a script and variable would be better, but I'm lazy.) I do the NPM install manually because it used to fail. Been using the same command since the 0.6.0 days, I'd guess. And I add the log at the end so that if I look away, I always see the log scrolling to know that things are okay.