Go "internal error: package without types was imported" - Fix in CI

This internal compiler error means Go tried to use a package whose type information was missing - almost always a corrupted or mismatched build cache rather than a fault in your code.

What this error means

A build fails with internal error: package "X" without types was imported from "Y". It often surfaces after a toolchain change, a shared cache between Go versions, or a partially populated build cache.

internal error: package "github.com/foo/bar" without types was imported from "example.com/app"

Common causes

Stale or mixed build cache

A build cache populated by one Go version is reused by another, leaving type info inconsistent.

Corrupted cache entry

A partially written cache entry has package data but no type export, tripping the internal check.

How to fix it

Clean the build cache and rebuild

Clear the Go build cache so the package is recompiled from scratch.

Terminal

go clean -cache
go build ./...

Key the cache on the Go version

Include the Go version in the build-cache key so different toolchains never share a cache.

.github/workflows/ci.yml

- uses: actions/cache@v4
  with:
    path: ~/.cache/go-build
    key: go-build-${{ runner.os }}-${{ env.GO_VERSION }}-${{ hashFiles('**/go.sum') }}

How to prevent it

Key the build cache on the Go version so toolchains never share it.
Run go clean -cache when switching Go versions locally.
Pin a single Go version per job.