Improve Bootsnap behaviour

- further refactor nested conditional to make it clearer
- allow running on Linux while still excluding Apple Silicon
- only warn on `bundle install` failures

Library/Homebrew/homebrew_bootsnap.rb

@@ -1,32 +1,30 @@
 # typed: false
 # frozen_string_literal: true
 
-homebrew_bootsnap_enabled = !ENV["HOMEBREW_NO_BOOTSNAP"] &&
-                            ENV["HOMEBREW_BOOTSNAP"] &&
-                            # portable ruby doesn't play nice with bootsnap
-                            !ENV["HOMEBREW_FORCE_VENDOR_RUBY"] &&
-                            (!ENV["HOMEBREW_MACOS_VERSION"] || ENV["HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH"]) &&
-                            # Apple Silicon doesn't play nice with bootsnap
-                            (ENV["HOMEBREW_PROCESSOR"] == "Intel")
-
-# we need some development tools to build bootsnap native code
-development_tools_installed = if !homebrew_bootsnap_enabled
-  false
-elsif RbConfig::CONFIG["host_os"].include? "darwin"
-  File.directory?("/Applications/Xcode.app") || File.directory?("/Library/Developer/CommandLineTools")
+homebrew_bootsnap_enabled = !ENV["HOMEBREW_NO_BOOTSNAP"] && ENV["HOMEBREW_BOOTSNAP"]
+
+# portable ruby doesn't play nice with bootsnap
+# Can't use .exclude? here because we haven't required active_support yet.
+homebrew_bootsnap_enabled &&= !ENV["HOMEBREW_RUBY_PATH"].to_s.include?("/vendor/portable-ruby/") # rubocop:disable Rails/NegateInclude
+
+homebrew_bootsnap_enabled &&= if ENV["HOMEBREW_MACOS_VERSION"]
+  # Apple Silicon doesn't play nice with bootsnap
+  ENV["HOMEBREW_PROCESSOR"] == "Intel" &&
+    # we need some development tools to build bootsnap native code
+    (File.directory?("/Applications/Xcode.app") || File.directory?("/Library/Developer/CommandLineTools"))
 else
   File.executable?("/usr/bin/clang") || File.executable?("/usr/bin/gcc")
 end
 
-if homebrew_bootsnap_enabled && development_tools_installed
+if homebrew_bootsnap_enabled
   require "rubygems"
 
   begin
     require "bootsnap"
   rescue LoadError
     unless ENV["HOMEBREW_BOOTSNAP_RETRY"]
       require "utils/gems"
-      Homebrew.install_bundler_gems!
+      Homebrew.install_bundler_gems!(only_warn_on_failure: true)
 
       ENV["HOMEBREW_BOOTSNAP_RETRY"] = "1"
       exec ENV["HOMEBREW_BREW_FILE"], *ARGV