Remove unused writer methods for Hbc.caskroom and Hbc.cache.

Library/Homebrew/cask/lib/hbc/locations.rb

@@ -7,14 +7,10 @@ module Hbc
     end
 
     module ClassMethods
-      attr_writer :caskroom
-
       def caskroom
         @caskroom ||= HOMEBREW_PREFIX.join("Caskroom")
       end
 
-      attr_writer :cache
-
       def cache
         @cache ||= HOMEBREW_CACHE.join("Cask")
       end

Library/Homebrew/compat/hbc/cli.rb

@@ -12,8 +12,7 @@ module Hbc
     end)
 
     option "--caskroom=PATH", (lambda do |value|
-      Hbc.caskroom = value
+      odisabled "`brew cask` with the `--caskroom` flag"
-      odeprecated "`brew cask` with the `--caskroom` flag", disable_on: Time.utc(2017, 10, 31)
     end)
   end
 end

Library/Homebrew/test/support/helper/spec/shared_context/homebrew_cask.rb

@@ -8,8 +8,6 @@ require "test/support/helper/cask/never_sudo_system_command"
 
 HOMEBREW_CASK_DIRS = [
   :appdir,
-  :caskroom,
-  :cache,
   :prefpanedir,
   :qlplugindir,
   :servicedir,
@@ -20,6 +18,8 @@ RSpec.shared_context "Homebrew-Cask" do
   around(:each) do |example|
     third_party_tap = Tap.fetch("third-party", "tap")
     begin
+      [Hbc.caskroom, Hbc.cache].each(&:mkpath)
+
       dirs = HOMEBREW_CASK_DIRS.map do |dir|
         Pathname.new(TEST_TMPDIR).join("cask-#{dir}").tap do |path|
           path.mkpath
@@ -40,6 +40,7 @@ RSpec.shared_context "Homebrew-Cask" do
       example.run
     ensure
       FileUtils.rm_rf dirs
+      FileUtils.rm_rf Hbc.caskroom, Hbc.cache
       Hbc.default_tap.path.unlink
       FileUtils.rm_rf Hbc.default_tap.path.parent
       third_party_tap.path.unlink