Go vet "composite literal uses unkeyed fields" - Fix in CI

By Daniel Zoghalchali·Latchkey

go vet warns when a struct literal from another package omits field names. Positional literals break silently when the struct gains or reorders fields, so vet flags them - and CI that gates on vet fails.

What this error means

A vet or test run fails with composite literal uses unkeyed fields. It commonly appears for literals of types from imported packages, especially after a dependency added a field.

./main.go:18:14: github.com/foo/bar.Config composite literal uses unkeyed fields

Diagnose it: toolchain, tags, or platform?

Go build failures that only appear in CI usually come from a different toolchain version, different build tags, or cross-compilation defaults that differ from your machine.

go version
go env GOOS GOARCH CGO_ENABLED GOFLAGS GOTOOLCHAIN

# build exactly what CI builds, verbosely
go build -v ./... 2>&1 | tail -40

# CGO is the usual difference: on by default locally, often off in a slim CI image
CGO_ENABLED=0 go build ./...

Common causes

Positional literal of an imported struct

A struct from another package is initialized by position, so any field change silently shifts values.

vet gated in CI

go test runs vet by default, so the warning becomes a hard failure in the pipeline.

How to fix it

Use keyed fields

1. Rewrite the literal to name each field so it is robust to struct changes.

cfg := bar.Config{
	Host: "localhost",
	Port: 8080,
}

Run vet locally before pushing

1. Run go vet to catch unkeyed literals before CI does.

go vet ./...

How to prevent it

• Always key struct literals of imported types.
• Run go vet ./... before pushing.
• Let your editor or gofmt enforce keyed fields.

Frequently asked questions

Related guides

References

• Go documentation
• GitHub Actions documentation