env GO111MODULE=off
[short] skip

# go clean -testcache
# should work (see golang.org/issue/29757).
cd x
go test x_test.go
go clean -testcache
go test x_test.go
! stdout 'cached'


-- x/x_test.go --
package x_test
import (
    "testing"
)
func TestMain(t *testing.T) {
}