There is a useful linter named `errcheck` for Go which looks for swallowed or shadowed errors [1]. It's included in `gometalinter` [2] (which is worth running as part of the CI checks on any Go codebase).
Unfortunately, there are a number of correct uses of go that swallow errors. For example, fmt.Println returns an error, but you're just not going to see that error handled. Sometimes, it doesn't matter whether something has failed, because there's not a useful, proportionate thing you can do to respond to that failure. And it's not possible to know from machine examination which cases are which. I'm sure for some programs (grep?) a failure to emit a line to stdout is cause for failure. But for most it is not.