[AnimalMuppet]

I would be astonished if there isn't an automated tool to check for that at the push of a button. I would be mildly surprised if there isn't a compiler flag to check for it.

[arp242]

Not a compiler check, but staticcheck is widely used:

    % staticcheck test.go
    test.go:7:2: this value of err is never used (SA4006)

[dmitshur]

Yeah, as one data point, https://staticcheck.dev/docs/checks/#SA4006 has existed since 2017.

[masklinn]

There very much is not. There is a compiler error you can’t disable if a variable is completely unused and that is it.