From aa6f10ff356e6bae2b53ee1c7cdafa26aa4c3ded Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?fn=20=E2=8C=83=20=E2=8C=A5?=
 <70830482+FnControlOption@users.noreply.github.com>
Date: Sun, 31 Oct 2021 10:52:40 -0700
Subject: [PATCH] install, upgrade: fetch each formula only once

---
 Library/Homebrew/formula_installer.rb | 13 +++++++++++++
 Library/Homebrew/test/spec_helper.rb  |  1 +
 2 files changed, 14 insertions(+)

diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index cab34ccc8c..ffdeed7af5 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -114,6 +114,15 @@ class FormulaInstaller
     @installed = Set.new
   end
 
+  def self.fetched
+    @fetched ||= Set.new
+  end
+
+  sig { void }
+  def self.clear_fetched
+    @fetched = Set.new
+  end
+
   sig { returns(T::Boolean) }
   def build_from_source?
     @build_from_source_formulae.include?(formula.full_name)
@@ -1141,6 +1150,8 @@ class FormulaInstaller
 
   sig { void }
   def fetch
+    return if self.class.fetched.include?(formula)
+
     fetch_dependencies
 
     return if only_deps?
@@ -1152,6 +1163,8 @@ class FormulaInstaller
       formula.resources.each(&:fetch)
     end
     downloader.fetch
+
+    self.class.fetched << formula
   end
 
   def downloader
diff --git a/Library/Homebrew/test/spec_helper.rb b/Library/Homebrew/test/spec_helper.rb
index 2bc564f8c1..cca75d7834 100644
--- a/Library/Homebrew/test/spec_helper.rb
+++ b/Library/Homebrew/test/spec_helper.rb
@@ -204,6 +204,7 @@ RSpec.configure do |config|
     Requirement.clear_cache
     FormulaInstaller.clear_attempted
     FormulaInstaller.clear_installed
+    FormulaInstaller.clear_fetched
 
     TEST_DIRECTORIES.each(&:mkpath)