From 95cfbff731f982c1db8e84b2ca8857459f969961 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ana=C3=AFs=20Saraiva?=
 <53227802+Kisakay@users.noreply.github.com>
Date: Wed, 22 Jul 2026 10:03:26 +0200
Subject: [PATCH] Update runner.ts

---
 apps/api/src/docker/runner.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/apps/api/src/docker/runner.ts b/apps/api/src/docker/runner.ts
index 7ae7c7b..c665401 100644
--- a/apps/api/src/docker/runner.ts
+++ b/apps/api/src/docker/runner.ts
@@ -95,7 +95,11 @@ export const runDocker = async (
       throw new HttpError(504, "Docker Mailserver command timed out.");
     }
 
-    throw new HttpError(502, "Docker Mailserver is unreachable.");
+    if (error instanceof Error && "code" in error && error.code === "ENOENT") {
+      throw new HttpError(502, `Docker binary '${config.dockerBinary}' was not found. Set DOCKER_BINARY to the absolute docker path on NixOS.`);
+    }
+
+    throw new HttpError(502, error instanceof Error ? error.message : "Docker Mailserver is unreachable.");
   } finally {
     clearTimeout(timeout);
   }