diff --git a/cmd/review-bot/main_test.go b/cmd/review-bot/main_test.go
index 6b8d75b..e9d32c8 100644
--- a/cmd/review-bot/main_test.go
+++ b/cmd/review-bot/main_test.go
@@ -1521,6 +1521,8 @@ func TestMainSubprocess_InvalidDocMapPath(t *testing.T) {
 	}
 
 	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_InvalidDocMapPath")
+	// t.TempDir() is evaluated here in the outer process, producing a real directory
+	// that is passed as the GITHUB_WORKSPACE env var string to the subprocess.
 	cmd.Env = append(cleanEnv(),
 		"TEST_SUBPROCESS_MAIN=1",
 		"GITHUB_WORKSPACE="+t.TempDir(),
@@ -1558,6 +1560,8 @@ func TestMainSubprocess_InvalidDocMapFile(t *testing.T) {
 	}
 
 	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_InvalidDocMapFile")
+	// t.TempDir() is evaluated here in the outer process, producing a real directory
+	// that is passed as the GITHUB_WORKSPACE env var string to the subprocess.
 	cmd.Env = append(cleanEnv(),
 		"TEST_SUBPROCESS_MAIN=1",
 		"GITHUB_WORKSPACE="+t.TempDir(),