From d85c87c28849da2a13e428ec1c43d14285085fbe Mon Sep 17 00:00:00 2001
From: Arnaud <arnaud@status.im>
Date: Wed, 24 Dec 2025 10:28:58 +0400
Subject: [PATCH] Provide better message a file is not found

---
 nix/tools.nix | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/nix/tools.nix b/nix/tools.nix
index 108d3860..47e99450 100644
--- a/nix/tools.nix
+++ b/nix/tools.nix
@@ -9,7 +9,12 @@ in {
     let
       linesFrom = file: splitString "\n" (fileContents file);
       matching = regex: lines: map (line: match regex line) lines;
-      extractMatch = matches: last (flatten (remove null matches));
+      extractMatch = matches:
+        let xs = flatten (remove null matches);
+        in if xs == [] then
+          throw "findKeyValue: no match for regex '${regex}' in ${toString sourceFile}"
+        else
+          last xs;
     in
       extractMatch (matching regex (linesFrom sourceFile));
 }