From c5a846b191e4bfa59346381d80de97508080eac2 Mon Sep 17 00:00:00 2001
From: Catherine <whitequark@whitequark.org>
Date: Sat, 18 May 2024 04:50:10 +0000
Subject: [PATCH] Do not depend on Nix tools in `fetch_local_hash`.

---
 lib/bundix/source.rb | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/bundix/source.rb b/lib/bundix/source.rb
index 33a942a..00a1904 100644
--- a/lib/bundix/source.rb
+++ b/lib/bundix/source.rb
@@ -1,3 +1,5 @@
+require 'digest/sha2'
+
 class Bundix
   class Fetcher
     def sh(*args, &block)
@@ -111,7 +113,11 @@ def fetch_local_hash(spec)
       spec.source.caches.each do |cache|
         path = File.join(cache, "#{spec.full_name}.gem")
         next unless File.file?(path)
-        hash = nix_prefetch_url(path)&.[](SHA256_32)
+        hash = Digest::SHA256.file(path).digest.bytes
+          .reverse
+          .reduce(0) {|n, b| (n << 8) + b }
+          .digits(32).map {|d| "0123456789abcdfghijklmnpqrsvwxyz"[d] }.join.ljust(52, '0')
+          .reverse
         return format_hash(hash) if hash
       end