nixbld: add some error handling to hydra-binary-cache-store.patch

nixbld-etc-nixos/hydra-binary-cache-store.patch

@@ -222,3 +222,30 @@ index 4276f95a..21ff8a97 100644
 -- 
 2.29.0
 
+From e20013bff3c92b21bab6e476489a1508df1cf348 Mon Sep 17 00:00:00 2001
+From: Astro <astro@spaceboyz.net>
+Date: Mon, 22 Feb 2021 00:12:12 +0100
+Subject: [PATCH] check if nar not found
+
+---
+ src/lib/Hydra/Controller/Root.pm | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/src/lib/Hydra/Controller/Root.pm b/src/lib/Hydra/Controller/Root.pm
+index 6be9f2bc..37464c34 100644
+--- a/src/lib/Hydra/Controller/Root.pm
++++ b/src/lib/Hydra/Controller/Root.pm
+@@ -326,6 +326,10 @@ sub nar :Local :Args(1) {
+         $c->response->content_type('application/x-nix-archive');
+ 
+         $path = "/" . $1 . "/nar/$path";
++        if (!-f $path) {
++            return notFound($c, "NAR not found");
++        }
++
+         my $fh = new IO::Handle;
+         open $fh, "<:raw", $path;
+         $c->response->body($fh);
+-- 
+2.30.0
+