From 0f8cb8416ec0f8021bdc00613b220b2773646d96 Mon Sep 17 00:00:00 2001
From: Aliaksei Kandratsenka <alkondratenko@gmail.com>
Date: Mon, 30 Sep 2024 12:23:52 -0400
Subject: [PATCH] [sampling_test] print errno when mkstemp fails

I see rare occasional failures there, which look very odd. Typically
both sampling and sampling_debug tests fail at about the same time. So
hopefully we can diagnose them sometime.
---
 src/tests/sampling_test.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tests/sampling_test.cc b/src/tests/sampling_test.cc
index 6ea64a9..f127624 100644
--- a/src/tests/sampling_test.cc
+++ b/src/tests/sampling_test.cc
@@ -163,6 +163,9 @@ struct TempFile {
     CHECK_EQ(it, path_template.get() + len);
 
     int fd = mkstemp(path_template.get());
+    if (fd < 0) {
+      perror("mkstemp");
+    }
     CHECK_GE(fd, 0);
 
     return TempFile{fdopen(fd, "r+"), std::string(path_template.get(), len-1)};