image_list.go is one of the files included in the non-test variant Go build list, but its getSampleDevicePluginPod function references readDaemonSetV1OrDie function defined in device_plugin_test.go which is included in the test variant Go build list only. (The file name is *_test.go).
As a result, "go build" fails with the undefined reference error.
In practice, that may not be an issue since k8s project contributors aren't meant to run go build on this package. However, tools that depend on go build to operate - e.g., gopls or govulncheck ./... - will report this as an error.
Fix this error and make test/e2e package pass go build by moving this file to also test-only source code.
17c17da97b