From ae457a80286d168b1adf9486f74d12fad503f964 Mon Sep 17 00:00:00 2001
From: Rylan Polster <rslpolster@gmail.com>
Date: Sat, 30 Oct 2021 23:54:01 -0400
Subject: [PATCH] Fix loading formulae from core tap

---
 Library/Homebrew/dependency.rb        | 5 -----
 Library/Homebrew/formula_installer.rb | 5 +++++
 Library/Homebrew/formulary.rb         | 7 +++++++
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/Library/Homebrew/dependency.rb b/Library/Homebrew/dependency.rb
index 79874077d5..aa5375112a 100644
--- a/Library/Homebrew/dependency.rb
+++ b/Library/Homebrew/dependency.rb
@@ -44,11 +44,6 @@ class Dependency
     formula = Formulary.factory(name)
     formula.build = BuildOptions.new(options, formula.options)
     formula
-  rescue CoreTapFormulaUnavailableError
-    raise if !Homebrew::EnvConfig.install_from_api? || !Homebrew::API::Bottle.available?(name)
-
-    Homebrew::API::Bottle.fetch_bottles(name)
-    retry
   end
 
   def unavailable_core_formula?
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 4c3fd9e547..51dc58f2d4 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -212,6 +212,11 @@ class FormulaInstaller
   def verify_deps_exist
     begin
       compute_dependencies
+    rescue CoreTapFormulaUnavailableError => e
+      raise unless Homebrew::API::Bottle.available? e.name
+
+      Homebrew::API::Bottle.fetch_bottles(e.name)
+      retry
     rescue TapFormulaUnavailableError => e
       raise if e.tap.installed? || e.tap.core_tap?
 
diff --git a/Library/Homebrew/formulary.rb b/Library/Homebrew/formulary.rb
index ed492477a6..768e49bb7e 100644
--- a/Library/Homebrew/formulary.rb
+++ b/Library/Homebrew/formulary.rb
@@ -535,6 +535,13 @@ module Formulary
     when URL_START_REGEX
       return FromUrlLoader.new(ref)
     when HOMEBREW_TAP_FORMULA_REGEX
+      # If `homebrew/core` is specified and not installed, check whether the formula is already installed.
+      if ref.start_with?("homebrew/core/") && !CoreTap.instance.installed? && Homebrew::EnvConfig.install_from_api?
+        name = ref.split("/", 3).last
+        possible_keg_formula = Pathname.new("#{HOMEBREW_PREFIX}/opt/#{name}/.brew/#{name}.rb")
+        return FormulaLoader.new(name, possible_keg_formula) if possible_keg_formula.file?
+      end
+
       return TapLoader.new(ref, from: from)
     end