diff --git a/src/pkg/os/exec/exec_test.go b/src/pkg/os/exec/exec_test.go
index a015cbe96cc..d7e61e73795 100644
--- a/src/pkg/os/exec/exec_test.go
+++ b/src/pkg/os/exec/exec_test.go
@@ -262,6 +262,7 @@ func TestHelperProcess(*testing.T) {
 			f, err := os.Open(os.Args[0])
 			if err != nil {
 				fmt.Printf("error opening file with expected fd %d: %v", wantfd, err)
+				fmt.Println(Command("lsof", "-p", fmt.Sprint(os.Getpid())).CombinedOutput())
 				os.Exit(1)
 			}
 			if got := f.Fd(); got != wantfd {