Pass args.cc to Install.

Library/Homebrew/cmd/gist-logs.rb

@@ -144,8 +144,8 @@ module Homebrew
   def gist_logs
     gist_logs_args.parse
 
-    perform_preinstall_checks(all_fatal: true)
+    Install.perform_preinstall_checks(all_fatal: true)
-    perform_build_from_source_checks(all_fatal: true)
+    Install.perform_build_from_source_checks(all_fatal: true)
     gistify_logs(args.resolved_formulae.first)
   end
 end

Library/Homebrew/cmd/install.rb

@@ -10,7 +10,6 @@ require "cli/parser"
 require "upgrade"
 
 module Homebrew
-  extend Install
   extend Search
 
   module_function
@@ -256,7 +255,7 @@ module Homebrew
 
     return if formulae.empty?
 
-    perform_preinstall_checks
+    Install.perform_preinstall_checks(cc: args.cc)
 
     formulae.each do |f|
       Migrator.migrate_if_needed(f, force: args.force?)

Library/Homebrew/cmd/reinstall.rb

@@ -13,8 +13,6 @@ require "cask/macos"
 require "upgrade"
 
 module Homebrew
-  extend Install
-
   module_function
 
   def reinstall_args
@@ -61,7 +59,7 @@ module Homebrew
 
     FormulaInstaller.prevent_build_flags unless DevelopmentTools.installed?
 
-    perform_preinstall_checks
+    Install.perform_preinstall_checks
 
     resolved_formulae, casks = args.resolved_formulae_casks
     resolved_formulae.each do |f|

Library/Homebrew/cmd/upgrade.rb

@@ -9,8 +9,6 @@ require "cask/utils"
 require "cask/macos"
 
 module Homebrew
-  extend Install
-
   module_function
 
   def upgrade_args
@@ -79,7 +77,7 @@ module Homebrew
   def upgrade_outdated_formulae(formulae)
     FormulaInstaller.prevent_build_flags unless DevelopmentTools.installed?
 
-    perform_preinstall_checks
+    Install.perform_preinstall_checks
 
     if formulae.blank?
       outdated = Formula.installed.select do |f|

Library/Homebrew/extend/os/linux/install.rb

@@ -43,8 +43,8 @@ module Homebrew
       FileUtils.ln_sf ld_so, brew_ld_so
     end
 
-    def perform_preinstall_checks(all_fatal: false)
+    def perform_preinstall_checks(all_fatal: false, cc: nil)
-      generic_perform_preinstall_checks(all_fatal: all_fatal)
+      generic_perform_preinstall_checks(all_fatal: all_fatal, cc: cc)
       symlink_ld_so
     end
   end

Library/Homebrew/install.rb

@@ -7,6 +7,8 @@ require "development_tools"
 
 module Homebrew
   module Install
+    module_function
+
     def check_cpu
       return if Hardware::CPU.intel? && Hardware::CPU.is_64_bit?
 
@@ -37,8 +39,8 @@ module Homebrew
       end
     end
 
-    def check_cc_argv
+    def check_cc_argv(cc)
-      return unless (cc = args.cc)
+      return unless cc
 
       @checks ||= Diagnostic::Checks.new
       opoo <<~EOS
@@ -47,10 +49,10 @@ module Homebrew
       EOS
     end
 
-    def perform_preinstall_checks(all_fatal: false)
+    def perform_preinstall_checks(all_fatal: false, cc: nil)
       check_cpu
       attempt_directory_creation
-      check_cc_argv
+      check_cc_argv(cc)
       diagnostic_checks(:supported_configuration_checks, fatal: all_fatal)
       diagnostic_checks(:fatal_preinstall_checks)
     end