Pass debug? to Formula#brew and Formula#run_test.

Library/Homebrew/build.rb

@@ -139,7 +139,7 @@ class Build
 
       formula.update_head_version
 
-      formula.brew(fetch: false, keep_tmp: args.keep_tmp?, interactive: args.interactive?) do |_formula, _staging|
+      formula.brew(fetch: false, keep_tmp: args.keep_tmp?, interactive: args.interactive?, debug: args.debug?) do
         # For head builds, HOMEBREW_FORMULA_PREFIX should include the commit,
         # which is not known until after the formula has been staged.
         ENV["HOMEBREW_FORMULA_PREFIX"] = formula.prefix

Library/Homebrew/dev-cmd/unpack.rb

@@ -57,7 +57,7 @@ module Homebrew
 
       # show messages about tar
       with_env VERBOSE: "1" do
-        f.brew do
+        f.brew(debug: args.debug?) do
           f.patch if args.patch?
           cp_r getwd, stage_dir, preserve: true
         end

Library/Homebrew/formula.rb

@@ -1170,7 +1170,7 @@ class Formula
   # yields |self,staging| with current working directory set to the uncompressed tarball
   # where staging is a Mktemp staging context
   # @private
-  def brew(fetch: true, keep_tmp: false, interactive: false)
+  def brew(fetch: true, keep_tmp: false, interactive: false, debug: false)
     @prefix_returns_versioned_prefix = true
     active_spec.fetch if fetch
     stage(interactive: interactive) do |staging|
@@ -1182,7 +1182,7 @@ class Formula
       begin
         yield self, staging
       rescue
-        staging.retain! if interactive || Homebrew.args.debug?
+        staging.retain! if interactive || debug
         raise
       ensure
         cp Dir["config.log", "CMakeCache.txt"], logs
@@ -1803,7 +1803,7 @@ class Formula
   end
 
   # @private
-  def run_test(keep_tmp: false)
+  def run_test(keep_tmp: false, debug: false)
     @prefix_returns_versioned_prefix = true
 
     test_env = {
@@ -1831,7 +1831,7 @@ class Formula
           end
         end
       rescue Exception # rubocop:disable Lint/RescueException
-        staging.retain! if Homebrew.args.debug?
+        staging.retain! if debug
         raise
       end
     end

Library/Homebrew/test.rb

@@ -34,7 +34,7 @@ begin
 
   # tests can also return false to indicate failure
   Timeout.timeout TEST_TIMEOUT_SECONDS do
-    raise "test returned false" if formula.run_test(keep_tmp: args.keep_tmp?) == false
+    raise "test returned false" if formula.run_test(keep_tmp: args.keep_tmp?, debug: args.debug?) == false
   end
 rescue Exception => e # rubocop:disable Lint/RescueException
   error_pipe.puts e.to_json