var pkgExts = [...]string{".a", ".o"} // a file from the build cache will have no extension

// FindPkg returns the filename and unique package id for an import
// path based on package information provided by build.Import (using
// the build.Default build.Context). A relative srcDir is interpreted
// relative to the current working directory.
func FindPkg(path, srcDir string) (filename, id string, err error) {
	if path == "" {

	{"math.Pi", "const Pi untyped float"},
	{"math.Sin", "func Sin(x float64) float64"},
	{"go/ast.NotNilFilter", "func NotNilFilter(_ string, v reflect.Value) bool"},
	{"go/internal/gcimporter.FindPkg", "func FindPkg(path string, srcDir string) (filename string, id string, err error)"},

	// interfaces