declared and not used — how to fix

./main.go:8:2: declared and not used: result

Quick fix: Remove the variable, or replace its name with _ if you need the call but not the value: _, err := doThing(). Temporarily silence it with _ = result.

What it means

Go treats an unused local variable as a compile error, not a warning. The idea is that an unused variable usually means a bug, such as assigning to the wrong variable. (Older Go versions phrase it result declared but not used.)

Fix 1: you don't need the value

// before
result, err := compute()
if err != nil { return err }

// after
_, err := compute()
if err != nil { return err }

Fix 2: you'll use it later (temporary while coding)

_ = result

Remove it before committing.

The sneaky case: shadowing with :=

var conn *Conn
if cfg.TLS {
    conn, err := dialTLS()   // := creates a NEW conn inside the if block
    ...
}

The inner conn is declared and not used, and the outer conn stays nil. Use plain assignment:

var err error
if cfg.TLS {
    conn, err = dialTLS()
}

go vet with the shadow analyzer, or golangci-lint, can catch these.

Package-level variables

The rule only applies inside functions. Unused package-level vars and unused function parameters compile fine.

Last updated 2026-10-27.