// result in an error.
	GoVersion string

	// If IgnoreFuncBodies is set, function bodies are not
	// type-checked.
	IgnoreFuncBodies bool

	// If FakeImportC is set, `import "C"` (for packages requiring Cgo)
	// declares an empty "C" package and errors are omitted for qualified
	// identifiers referring to package C (which won't find an object).

	//          Do not use casually!
	FakeImportC bool

	// If go115UsesCgo is set, the type checker expects the
	// _cgo_gotypes.go file generated by running cmd/cgo to be
	// provided as a package source file. Qualified identifiers
	// referring to package C will be resolved to cgo-provided
	// declarations within _cgo_gotypes.go.
	//
	// It is an error to set both FakeImportC and go115UsesCgo.
	go115UsesCgo bool

	var goexperiment, gotypesalias string
	flags := flag.NewFlagSet("", flag.PanicOnError)
	flags.StringVar(&conf.GoVersion, "lang", "", "")
	flags.StringVar(&goexperiment, "goexperiment", "", "")
	flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
	flags.StringVar(&gotypesalias, "gotypesalias", "", "")
	if err := parseFlags(srcs[0], flags); err != nil {
		t.Fatal(err)
	}

	var goexperiment, gotypesalias string
	flags := flag.NewFlagSet("", flag.PanicOnError)
	flags.StringVar(&conf.GoVersion, "lang", "", "")
	flags.StringVar(&goexperiment, "goexperiment", "", "")
	flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
	flags.StringVar(&gotypesalias, "gotypesalias", "", "")
	if err := parseFlags(srcs[0], flags); err != nil {
		t.Fatal(err)
	}

	imp := check.impMap[key]
	if imp != nil {
		return imp
	}

	// no package yet => import it
	if path == "C" && (check.conf.FakeImportC || check.conf.go115UsesCgo) {
		if check.conf.FakeImportC && check.conf.go115UsesCgo {
			check.error(at, BadImportPath, "cannot use FakeImportC and go115UsesCgo together")
		}
		imp = NewPackage("C", "C")
		imp.fake = true // package scope is not populated