I don't want to get into a debate about what "inheritance" means, but html/template does support template composition and nested templates, which seem to address the same use case.
> These two problems have made it so I've pretty much given up web apps in Go for now. Services in Go are _amazing_. But if you're trying to get a full blown web app (again, not the point of the linked article above), then you're gonna have a bad time.
I'm sorry to hear that, especially since writing a "full-blown web app" is really not difficult in Go at all, once you know what you're doing.
I've actually been working on Jetpack[0], a sample web application in Go to demonstrate how straightforward this is, once one understands how it actually works. (Disclaimer: it's still a work in progress, so it's not complete/ready yet).