From debf955f8d50257beeae5f0aba171d5a691b2910 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Thu, 7 May 2026 19:00:23 -0500
Subject: [PATCH] [host][ota] Log execv() failure on OTA re-exec

execv only returns on failure. Surface the errno so a missing or
non-executable staged binary is diagnosable instead of silently
falling back to exit(0).
---
 esphome/components/host/hal.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/esphome/components/host/hal.cpp b/esphome/components/host/hal.cpp
index 4f4ca839d1..9108c1ea9d 100644
--- a/esphome/components/host/hal.cpp
+++ b/esphome/components/host/hal.cpp
@@ -2,12 +2,14 @@
 
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
 #include "core.h"
 
 #include <time.h>
 #include <unistd.h>
 #include <cerrno>
 #include <cstdlib>
+#include <cstring>
 
 // Empty host namespace block to satisfy ci-custom's lint_namespace check.
 // HAL functions live in namespace esphome (root) — they are not part of the
@@ -57,7 +59,10 @@ void arch_restart() {
   if (const char *target = host::get_reexec_path()) {
     char **argv = host::get_argv();
     if (argv != nullptr) {
-      execv(target, argv);  // only returns on failure
+      execv(target, argv);
+      // execv only returns on failure.
+      ESP_LOGE("host", "execv('%s') failed: %s", target, std::strerror(errno));
+      exit(1);
     }
   }
   exit(0);