diff --git a/Library/Homebrew/cask/lib/hbc.rb b/Library/Homebrew/cask/lib/hbc.rb
index 737c930d10..5530683523 100644
--- a/Library/Homebrew/cask/lib/hbc.rb
+++ b/Library/Homebrew/cask/lib/hbc.rb
@@ -18,7 +18,7 @@ require "hbc/installer"
 require "hbc/macos"
 require "hbc/pkg"
 require "hbc/staged"
-require "hbc/system_command"
+require "system_command"
 require "hbc/topological_hash"
 require "hbc/utils"
 require "hbc/verify"
diff --git a/Library/Homebrew/cask/lib/hbc/dsl/appcast.rb b/Library/Homebrew/cask/lib/hbc/dsl/appcast.rb
index 8b52fcde2e..2472c88e49 100644
--- a/Library/Homebrew/cask/lib/hbc/dsl/appcast.rb
+++ b/Library/Homebrew/cask/lib/hbc/dsl/appcast.rb
@@ -1,4 +1,4 @@
-require "hbc/system_command"
+require "system_command"
 
 module Hbc
   class DSL
diff --git a/Library/Homebrew/cask/lib/hbc/system_command.rb b/Library/Homebrew/cask/lib/hbc/system_command.rb
deleted file mode 100644
index e86fa8f6c7..0000000000
--- a/Library/Homebrew/cask/lib/hbc/system_command.rb
+++ /dev/null
@@ -1,194 +0,0 @@
-require "open3"
-require "vendor/plist/plist"
-require "shellwords"
-
-require "extend/io"
-require "extend/hash_validator"
-using HashValidator
-
-module Hbc
-  class SystemCommand
-    extend Predicable
-
-    def self.run(executable, **options)
-      new(executable, **options).run!
-    end
-
-    def self.run!(command, **options)
-      run(command, **options, must_succeed: true)
-    end
-
-    def run!
-      @merged_output = []
-      @processed_output = { stdout: "", stderr: "" }
-      odebug command.shelljoin
-
-      each_output_line do |type, line|
-        case type
-        when :stdout
-          puts line.chomp if print_stdout?
-          processed_output[:stdout] << line
-          @merged_output << [:stdout, line]
-        when :stderr
-          $stderr.puts Formatter.error(line.chomp) if print_stderr?
-          processed_output[:stderr] << line
-          @merged_output << [:stderr, line]
-        end
-      end
-
-      assert_success if must_succeed?
-      result
-    end
-
-    def initialize(executable, args: [], sudo: false, input: [], print_stdout: false, print_stderr: true, must_succeed: false, env: {}, **options)
-      @executable = executable
-      @args = args
-      @sudo = sudo
-      @input = [*input]
-      @print_stdout = print_stdout
-      @print_stderr = print_stderr
-      @must_succeed = must_succeed
-      options.assert_valid_keys!(:chdir)
-      @options = options
-      @env = env
-
-      @env.keys.grep_v(/^[\w&&\D]\w*$/) do |name|
-        raise ArgumentError, "Invalid variable name: '#{name}'"
-      end
-    end
-
-    def command
-      [*sudo_prefix, *env_args, executable.to_s, *expanded_args]
-    end
-
-    private
-
-    attr_reader :executable, :args, :input, :options, :processed_output, :processed_status, :env
-
-    attr_predicate :sudo?, :print_stdout?, :print_stderr?, :must_succeed?
-
-    def env_args
-      return [] if env.empty?
-
-      variables = env.map do |name, value|
-        sanitized_name = Shellwords.escape(name)
-        sanitized_value = Shellwords.escape(value)
-        "#{sanitized_name}=#{sanitized_value}"
-      end
-
-      ["env", *variables]
-    end
-
-    def sudo_prefix
-      return [] unless sudo?
-      askpass_flags = ENV.key?("SUDO_ASKPASS") ? ["-A"] : []
-      ["/usr/bin/sudo", *askpass_flags, "-E", "--"]
-    end
-
-    def assert_success
-      return if processed_status&.success?
-      raise ErrorDuringExecution.new(command,
-                                     status: processed_status,
-                                     output: @merged_output)
-    end
-
-    def expanded_args
-      @expanded_args ||= args.map do |arg|
-        if arg.respond_to?(:to_path)
-          File.absolute_path(arg)
-        elsif arg.is_a?(Integer) || arg.is_a?(Float)
-          arg.to_s
-        else
-          arg.to_str
-        end
-      end
-    end
-
-    def each_output_line(&b)
-      executable, *args = command
-
-      raw_stdin, raw_stdout, raw_stderr, raw_wait_thr =
-        Open3.popen3([executable, executable], *args, **options)
-
-      write_input_to(raw_stdin)
-      raw_stdin.close_write
-      each_line_from [raw_stdout, raw_stderr], &b
-
-      @processed_status = raw_wait_thr.value
-    end
-
-    def write_input_to(raw_stdin)
-      input.each(&raw_stdin.method(:write))
-    end
-
-    def each_line_from(sources)
-      loop do
-        readable_sources, = IO.select(sources)
-
-        readable_sources = readable_sources.reject(&:eof?)
-
-        break if readable_sources.empty?
-
-        readable_sources.each do |source|
-          begin
-            line = source.readline_nonblock || ""
-            type = (source == sources[0]) ? :stdout : :stderr
-            yield(type, line)
-          rescue IO::WaitReadable, EOFError
-            next
-          end
-        end
-      end
-
-      sources.each(&:close_read)
-    end
-
-    def result
-      Result.new(command,
-                 processed_output[:stdout],
-                 processed_output[:stderr],
-                 processed_status.exitstatus)
-    end
-
-    class Result
-      attr_accessor :command, :stdout, :stderr, :exit_status
-
-      def initialize(command, stdout, stderr, exit_status)
-        @command     = command
-        @stdout      = stdout
-        @stderr      = stderr
-        @exit_status = exit_status
-      end
-
-      def success?
-        @exit_status.zero?
-      end
-
-      def plist
-        @plist ||= begin
-          output = stdout
-
-          if /\A(?<garbage>.*?)<\?\s*xml/m =~ output
-            output = output.sub(/\A#{Regexp.escape(garbage)}/m, "")
-            warn_plist_garbage(garbage)
-          end
-
-          if %r{<\s*/\s*plist\s*>(?<garbage>.*?)\Z}m =~ output
-            output = output.sub(/#{Regexp.escape(garbage)}\Z/, "")
-            warn_plist_garbage(garbage)
-          end
-
-          Plist.parse_xml(output)
-        end
-      end
-
-      def warn_plist_garbage(garbage)
-        return unless ARGV.verbose?
-        return unless garbage =~ /\S/
-        opoo "Received non-XML output from #{Formatter.identifier(command.first)}:"
-        $stderr.puts garbage.strip
-      end
-      private :warn_plist_garbage
-    end
-  end
-end
diff --git a/Library/Homebrew/cask/lib/hbc/verify/gpg.rb b/Library/Homebrew/cask/lib/hbc/verify/gpg.rb
index 16798d7fa1..088150d389 100644
--- a/Library/Homebrew/cask/lib/hbc/verify/gpg.rb
+++ b/Library/Homebrew/cask/lib/hbc/verify/gpg.rb
@@ -7,7 +7,7 @@ module Hbc
 
       attr_reader :cask, :downloaded_path
 
-      def initialize(cask, downloaded_path, command = Hbc::SystemCommand)
+      def initialize(cask, downloaded_path, command = SystemCommand)
         @command = command
         @cask = cask
         @downloaded_path = downloaded_path
diff --git a/Library/Homebrew/readall.rb b/Library/Homebrew/readall.rb
index 249987b33b..fb6fcac8a7 100644
--- a/Library/Homebrew/readall.rb
+++ b/Library/Homebrew/readall.rb
@@ -76,6 +76,13 @@ module Readall
       # Retrieve messages about syntax errors/warnings printed to `$stderr`, but
       # discard a `Syntax OK` printed to `$stdout` (in absence of syntax errors).
       messages = Utils.popen_read("#{RUBY_PATH} -c -w #{rb} 2>&1 >/dev/null")
+
+      # Ignore unnecessary warning about named capture conflicts.
+      # See https://bugs.ruby-lang.org/issues/12359.
+      messages = messages.lines
+                         .reject { |line| line.include?("named capture conflicts a local variable") }
+                         .join
+
       $stderr.print messages
 
       # Only syntax errors result in a non-zero status code. To detect syntax
diff --git a/Library/Homebrew/system_command.rb b/Library/Homebrew/system_command.rb
new file mode 100644
index 0000000000..8095acfd65
--- /dev/null
+++ b/Library/Homebrew/system_command.rb
@@ -0,0 +1,192 @@
+require "open3"
+require "vendor/plist/plist"
+require "shellwords"
+
+require "extend/io"
+require "extend/hash_validator"
+using HashValidator
+
+class SystemCommand
+  extend Predicable
+
+  def self.run(executable, **options)
+    new(executable, **options).run!
+  end
+
+  def self.run!(command, **options)
+    run(command, **options, must_succeed: true)
+  end
+
+  def run!
+    @merged_output = []
+    @processed_output = { stdout: "", stderr: "" }
+    odebug command.shelljoin
+
+    each_output_line do |type, line|
+      case type
+      when :stdout
+        puts line.chomp if print_stdout?
+        processed_output[:stdout] << line
+        @merged_output << [:stdout, line]
+      when :stderr
+        $stderr.puts Formatter.error(line.chomp) if print_stderr?
+        processed_output[:stderr] << line
+        @merged_output << [:stderr, line]
+      end
+    end
+
+    assert_success if must_succeed?
+    result
+  end
+
+  def initialize(executable, args: [], sudo: false, input: [], print_stdout: false, print_stderr: true, must_succeed: false, env: {}, **options)
+    @executable = executable
+    @args = args
+    @sudo = sudo
+    @input = [*input]
+    @print_stdout = print_stdout
+    @print_stderr = print_stderr
+    @must_succeed = must_succeed
+    options.assert_valid_keys!(:chdir)
+    @options = options
+    @env = env
+
+    @env.keys.grep_v(/^[\w&&\D]\w*$/) do |name|
+      raise ArgumentError, "Invalid variable name: '#{name}'"
+    end
+  end
+
+  def command
+    [*sudo_prefix, *env_args, executable.to_s, *expanded_args]
+  end
+
+  private
+
+  attr_reader :executable, :args, :input, :options, :processed_output, :processed_status, :env
+
+  attr_predicate :sudo?, :print_stdout?, :print_stderr?, :must_succeed?
+
+  def env_args
+    return [] if env.empty?
+
+    variables = env.map do |name, value|
+      sanitized_name = Shellwords.escape(name)
+      sanitized_value = Shellwords.escape(value)
+      "#{sanitized_name}=#{sanitized_value}"
+    end
+
+    ["env", *variables]
+  end
+
+  def sudo_prefix
+    return [] unless sudo?
+    askpass_flags = ENV.key?("SUDO_ASKPASS") ? ["-A"] : []
+    ["/usr/bin/sudo", *askpass_flags, "-E", "--"]
+  end
+
+  def assert_success
+    return if processed_status&.success?
+    raise ErrorDuringExecution.new(command,
+                                   status: processed_status,
+                                   output: @merged_output)
+  end
+
+  def expanded_args
+    @expanded_args ||= args.map do |arg|
+      if arg.respond_to?(:to_path)
+        File.absolute_path(arg)
+      elsif arg.is_a?(Integer) || arg.is_a?(Float)
+        arg.to_s
+      else
+        arg.to_str
+      end
+    end
+  end
+
+  def each_output_line(&b)
+    executable, *args = command
+
+    raw_stdin, raw_stdout, raw_stderr, raw_wait_thr =
+      Open3.popen3([executable, executable], *args, **options)
+
+    write_input_to(raw_stdin)
+    raw_stdin.close_write
+    each_line_from [raw_stdout, raw_stderr], &b
+
+    @processed_status = raw_wait_thr.value
+  end
+
+  def write_input_to(raw_stdin)
+    input.each(&raw_stdin.method(:write))
+  end
+
+  def each_line_from(sources)
+    loop do
+      readable_sources, = IO.select(sources)
+
+      readable_sources = readable_sources.reject(&:eof?)
+
+      break if readable_sources.empty?
+
+      readable_sources.each do |source|
+        begin
+          line = source.readline_nonblock || ""
+          type = (source == sources[0]) ? :stdout : :stderr
+          yield(type, line)
+        rescue IO::WaitReadable, EOFError
+          next
+        end
+      end
+    end
+
+    sources.each(&:close_read)
+  end
+
+  def result
+    Result.new(command,
+               processed_output[:stdout],
+               processed_output[:stderr],
+               processed_status.exitstatus)
+  end
+
+  class Result
+    attr_accessor :command, :stdout, :stderr, :exit_status
+
+    def initialize(command, stdout, stderr, exit_status)
+      @command     = command
+      @stdout      = stdout
+      @stderr      = stderr
+      @exit_status = exit_status
+    end
+
+    def success?
+      @exit_status.zero?
+    end
+
+    def plist
+      @plist ||= begin
+        output = stdout
+
+        if /\A(?<garbage>.*?)<\?\s*xml/m =~ output
+          output = output.sub(/\A#{Regexp.escape(garbage)}/m, "")
+          warn_plist_garbage(garbage)
+        end
+
+        if %r{<\s*/\s*plist\s*>(?<garbage>.*?)\Z}m =~ output
+          output = output.sub(/#{Regexp.escape(garbage)}\Z/, "")
+          warn_plist_garbage(garbage)
+        end
+
+        Plist.parse_xml(output)
+      end
+    end
+
+    def warn_plist_garbage(garbage)
+      return unless ARGV.verbose?
+      return unless garbage =~ /\S/
+      opoo "Received non-XML output from #{Formatter.identifier(command.first)}:"
+      $stderr.puts garbage.strip
+    end
+    private :warn_plist_garbage
+  end
+end
diff --git a/Library/Homebrew/test/cask/accessibility_spec.rb b/Library/Homebrew/test/cask/accessibility_spec.rb
index 26613aa20c..2ba7d2a8ae 100644
--- a/Library/Homebrew/test/cask/accessibility_spec.rb
+++ b/Library/Homebrew/test/cask/accessibility_spec.rb
@@ -2,7 +2,7 @@
 #       that class is abstracted from installer.rb.
 describe "Accessibility Access", :cask do
   let(:cask) { Hbc::CaskLoader.load(cask_path("with-accessibility-access")) }
-  let(:fake_system_command) { class_double(Hbc::SystemCommand) }
+  let(:fake_system_command) { class_double(SystemCommand) }
   let(:installer) { Hbc::Installer.new(cask, command: fake_system_command) }
 
   before do
diff --git a/Library/Homebrew/test/cask/artifact/alt_target_spec.rb b/Library/Homebrew/test/cask/artifact/alt_target_spec.rb
index 2168ac6063..e78a353e6c 100644
--- a/Library/Homebrew/test/cask/artifact/alt_target_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/alt_target_spec.rb
@@ -5,7 +5,7 @@ describe Hbc::Artifact::App, :cask do
     let(:install_phase) {
       lambda do
         cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-          artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+          artifact.install_phase(command: NeverSudoSystemCommand, force: false)
         end
       end
     }
diff --git a/Library/Homebrew/test/cask/artifact/app_spec.rb b/Library/Homebrew/test/cask/artifact/app_spec.rb
index aa6085bf16..305b3af37c 100644
--- a/Library/Homebrew/test/cask/artifact/app_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/app_spec.rb
@@ -1,6 +1,6 @@
 describe Hbc::Artifact::App, :cask do
   let(:cask) { Hbc::CaskLoader.load(cask_path("local-caffeine")) }
-  let(:command) { Hbc::SystemCommand }
+  let(:command) { SystemCommand }
   let(:force) { false }
   let(:app) { cask.artifacts.find { |a| a.is_a?(described_class) } }
 
diff --git a/Library/Homebrew/test/cask/artifact/binary_spec.rb b/Library/Homebrew/test/cask/artifact/binary_spec.rb
index 448c10dd1e..cdee0860f6 100644
--- a/Library/Homebrew/test/cask/artifact/binary_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/binary_spec.rb
@@ -24,7 +24,7 @@ describe Hbc::Artifact::Binary, :cask do
 
   it "links the binary to the proper directory" do
     artifacts.each do |artifact|
-      artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+      artifact.install_phase(command: NeverSudoSystemCommand, force: false)
     end
 
     expect(expected_path).to be_a_symlink
@@ -45,7 +45,7 @@ describe Hbc::Artifact::Binary, :cask do
         .with("+x", cask.staged_path.join("naked_non_executable")).and_call_original
 
       artifacts.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect(expected_path).to be_a_symlink
@@ -58,7 +58,7 @@ describe Hbc::Artifact::Binary, :cask do
 
     expect {
       artifacts.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
     }.to raise_error(Hbc::CaskError)
 
@@ -69,7 +69,7 @@ describe Hbc::Artifact::Binary, :cask do
     expected_path.make_symlink("/tmp")
 
     artifacts.each do |artifact|
-      artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+      artifact.install_phase(command: NeverSudoSystemCommand, force: false)
     end
 
     expect(File.readlink(expected_path)).not_to eq("/tmp")
@@ -79,7 +79,7 @@ describe Hbc::Artifact::Binary, :cask do
     FileUtils.rmdir Hbc::Config.global.binarydir
 
     artifacts.each do |artifact|
-      artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+      artifact.install_phase(command: NeverSudoSystemCommand, force: false)
     end
 
     expect(expected_path.exist?).to be true
@@ -94,10 +94,10 @@ describe Hbc::Artifact::Binary, :cask do
 
     it "links the binary to the proper directory" do
       cask.artifacts.select { |a| a.is_a?(Hbc::Artifact::App) }.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
       artifacts.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect(expected_path).to be_a_symlink
diff --git a/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb b/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb
index 5502d83ed7..981228917f 100644
--- a/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb
@@ -4,7 +4,7 @@ describe Hbc::Artifact::Artifact, :cask do
   let(:install_phase) {
     lambda do
       cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
     end
   }
diff --git a/Library/Homebrew/test/cask/artifact/installer_spec.rb b/Library/Homebrew/test/cask/artifact/installer_spec.rb
index 7e4c551125..d566440c0f 100644
--- a/Library/Homebrew/test/cask/artifact/installer_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/installer_spec.rb
@@ -2,7 +2,7 @@ describe Hbc::Artifact::Installer, :cask do
   let(:staged_path) { mktmpdir }
   let(:cask) { instance_double("Cask", staged_path: staged_path, config: nil) }
   subject(:installer) { described_class.new(cask, **args) }
-  let(:command) { Hbc::SystemCommand }
+  let(:command) { SystemCommand }
 
   let(:args) { {} }
 
diff --git a/Library/Homebrew/test/cask/artifact/nested_container_spec.rb b/Library/Homebrew/test/cask/artifact/nested_container_spec.rb
index f9cd056f8a..92486fc7f8 100644
--- a/Library/Homebrew/test/cask/artifact/nested_container_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/nested_container_spec.rb
@@ -6,7 +6,7 @@ describe Hbc::Artifact::NestedContainer, :cask do
       end
 
       cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect(cask.staged_path.join("MyNestedApp.app")).to be_a_directory
diff --git a/Library/Homebrew/test/cask/artifact/pkg_spec.rb b/Library/Homebrew/test/cask/artifact/pkg_spec.rb
index 74dfa5e5fd..4605eeaf81 100644
--- a/Library/Homebrew/test/cask/artifact/pkg_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/pkg_spec.rb
@@ -1,6 +1,6 @@
 describe Hbc::Artifact::Pkg, :cask do
   let(:cask) { Hbc::CaskLoader.load(cask_path("with-installable")) }
-  let(:fake_system_command) { class_double(Hbc::SystemCommand) }
+  let(:fake_system_command) { class_double(SystemCommand) }
 
   before do
     InstallHelper.install_without_artifacts(cask)
diff --git a/Library/Homebrew/test/cask/artifact/postflight_block_spec.rb b/Library/Homebrew/test/cask/artifact/postflight_block_spec.rb
index 18cc4ca91a..a49c900fcf 100644
--- a/Library/Homebrew/test/cask/artifact/postflight_block_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/postflight_block_spec.rb
@@ -12,7 +12,7 @@ describe Hbc::Artifact::PostflightBlock, :cask do
       end
 
       cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect(called).to be true
@@ -33,7 +33,7 @@ describe Hbc::Artifact::PostflightBlock, :cask do
       end
 
       cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-        artifact.uninstall_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.uninstall_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect(called).to be true
diff --git a/Library/Homebrew/test/cask/artifact/preflight_block_spec.rb b/Library/Homebrew/test/cask/artifact/preflight_block_spec.rb
index 405cdbd6f8..7a00839e27 100644
--- a/Library/Homebrew/test/cask/artifact/preflight_block_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/preflight_block_spec.rb
@@ -12,7 +12,7 @@ describe Hbc::Artifact::PreflightBlock, :cask do
       end
 
       cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect(called).to be true
@@ -33,7 +33,7 @@ describe Hbc::Artifact::PreflightBlock, :cask do
       end
 
       cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-        artifact.uninstall_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.uninstall_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect(called).to be true
diff --git a/Library/Homebrew/test/cask/artifact/suite_spec.rb b/Library/Homebrew/test/cask/artifact/suite_spec.rb
index 2602bb2ad0..55cd1d9ce5 100644
--- a/Library/Homebrew/test/cask/artifact/suite_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/suite_spec.rb
@@ -4,7 +4,7 @@ describe Hbc::Artifact::Suite, :cask do
   let(:install_phase) {
     lambda do
       cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
     end
   }
diff --git a/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb b/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb
index 7c5f862141..4c56428d78 100644
--- a/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb
@@ -5,7 +5,7 @@ describe Hbc::Artifact::App, :cask do
     let(:install_phase) {
       lambda do
         cask.artifacts.select { |a| a.is_a?(described_class) }.each do |artifact|
-          artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+          artifact.install_phase(command: NeverSudoSystemCommand, force: false)
         end
       end
     }
diff --git a/Library/Homebrew/test/cask/artifact/uninstall_zap_shared_examples.rb b/Library/Homebrew/test/cask/artifact/uninstall_zap_shared_examples.rb
index 7edfb9e1ce..31ed8d4ff4 100644
--- a/Library/Homebrew/test/cask/artifact/uninstall_zap_shared_examples.rb
+++ b/Library/Homebrew/test/cask/artifact/uninstall_zap_shared_examples.rb
@@ -1,7 +1,7 @@
 shared_examples "#uninstall_phase or #zap_phase" do
   let(:artifact_dsl_key) { described_class.dsl_key }
   let(:artifact) { cask.artifacts.find { |a| a.is_a?(described_class) } }
-  let(:fake_system_command) { Hbc::FakeSystemCommand }
+  let(:fake_system_command) { FakeSystemCommand }
 
   subject { artifact.public_send(:"#{artifact_dsl_key}_phase", command: fake_system_command) }
 
@@ -26,40 +26,40 @@ shared_examples "#uninstall_phase or #zap_phase" do
     end
 
     it "works when job is owned by user" do
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         launchctl_list_cmd,
         service_info,
       )
 
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         sudo(launchctl_list_cmd),
         unknown_response,
       )
 
-      Hbc::FakeSystemCommand.expects_command(launchctl_remove_cmd)
+      FakeSystemCommand.expects_command(launchctl_remove_cmd)
 
       subject
     end
 
     it "works when job is owned by system" do
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         launchctl_list_cmd,
         unknown_response,
       )
 
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         sudo(launchctl_list_cmd),
         service_info,
       )
 
-      Hbc::FakeSystemCommand.expects_command(sudo(launchctl_remove_cmd))
+      FakeSystemCommand.expects_command(sudo(launchctl_remove_cmd))
 
       subject
     end
   end
 
   context "using :pkgutil" do
-    let(:fake_system_command) { class_double(Hbc::SystemCommand) }
+    let(:fake_system_command) { class_double(SystemCommand) }
 
     let(:cask) { Hbc::CaskLoader.load(cask_path("with-#{artifact_dsl_key}-pkgutil")) }
 
@@ -89,19 +89,19 @@ shared_examples "#uninstall_phase or #zap_phase" do
     let(:kext_id) { "my.fancy.package.kernelextension" }
 
     it "is supported" do
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         sudo(%W[/usr/sbin/kextstat -l -b #{kext_id}]), "loaded"
       )
 
-      Hbc::FakeSystemCommand.expects_command(
+      FakeSystemCommand.expects_command(
         sudo(%W[/sbin/kextunload -b #{kext_id}]),
       )
 
-      Hbc::FakeSystemCommand.expects_command(
+      FakeSystemCommand.expects_command(
         sudo(%W[/usr/sbin/kextfind -b #{kext_id}]), "/Library/Extensions/FancyPackage.kext\n"
       )
 
-      Hbc::FakeSystemCommand.expects_command(
+      FakeSystemCommand.expects_command(
         sudo(["/bin/rm", "-rf", "/Library/Extensions/FancyPackage.kext"]),
       )
 
@@ -117,11 +117,11 @@ shared_examples "#uninstall_phase or #zap_phase" do
     end
 
     it "is supported" do
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         %w[/bin/launchctl list], "999\t0\t#{bundle_id}\n"
       )
 
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         %w[/bin/launchctl list],
       )
 
@@ -136,7 +136,7 @@ shared_examples "#uninstall_phase or #zap_phase" do
     let(:unix_pids) { [12_345, 67_890] }
 
     it "is supported" do
-      Hbc::FakeSystemCommand.stubs_command(
+      FakeSystemCommand.stubs_command(
         %w[/bin/launchctl list], unix_pids.map { |pid| [pid, 0, bundle_id].join("\t") }.join("\n")
       )
 
@@ -171,7 +171,7 @@ shared_examples "#uninstall_phase or #zap_phase" do
         end
       end
 
-      let(:fake_system_command) { Hbc::NeverSudoSystemCommand }
+      let(:fake_system_command) { NeverSudoSystemCommand }
       let(:cask) { Hbc::CaskLoader.load(cask_path("with-#{artifact_dsl_key}-#{directive}")) }
 
       before(:each) do
@@ -197,7 +197,7 @@ shared_examples "#uninstall_phase or #zap_phase" do
   end
 
   context "using :rmdir" do
-    let(:fake_system_command) { Hbc::NeverSudoSystemCommand }
+    let(:fake_system_command) { NeverSudoSystemCommand }
     let(:cask) { Hbc::CaskLoader.load(cask_path("with-#{artifact_dsl_key}-rmdir")) }
     let(:empty_directory) { Pathname.new("#{TEST_TMPDIR}/empty_directory_path") }
     let(:ds_store) { empty_directory.join(".DS_Store") }
@@ -224,7 +224,7 @@ shared_examples "#uninstall_phase or #zap_phase" do
 
   [:script, :early_script].each do |script_type|
     context "using #{script_type.inspect}" do
-      let(:fake_system_command) { Hbc::NeverSudoSystemCommand }
+      let(:fake_system_command) { NeverSudoSystemCommand }
       let(:token) { "with-#{artifact_dsl_key}-#{script_type}".tr("_", "-") }
       let(:cask) { Hbc::CaskLoader.load(cask_path(token.to_s)) }
       let(:script_pathname) { cask.staged_path.join("MyFancyPkg", "FancyUninstaller.tool") }
@@ -255,7 +255,7 @@ shared_examples "#uninstall_phase or #zap_phase" do
     let(:cask) { Hbc::CaskLoader.load(cask_path("with-#{artifact_dsl_key}-login-item")) }
 
     it "is supported" do
-      Hbc::FakeSystemCommand.expects_command(
+      FakeSystemCommand.expects_command(
         ["/usr/bin/osascript", "-e", 'tell application "System Events" to delete every login ' \
                                      'item whose name is "Fancy"'],
       )
diff --git a/Library/Homebrew/test/cask/audit_spec.rb b/Library/Homebrew/test/cask/audit_spec.rb
index 8d5b2fdd59..170af5b101 100644
--- a/Library/Homebrew/test/cask/audit_spec.rb
+++ b/Library/Homebrew/test/cask/audit_spec.rb
@@ -38,7 +38,7 @@ describe Hbc::Audit, :cask do
   let(:cask) { instance_double(Hbc::Cask) }
   let(:download) { false }
   let(:check_token_conflicts) { false }
-  let(:fake_system_command) { class_double(Hbc::SystemCommand) }
+  let(:fake_system_command) { class_double(SystemCommand) }
   let(:audit) {
     Hbc::Audit.new(cask, download:              download,
                          check_token_conflicts: check_token_conflicts,
diff --git a/Library/Homebrew/test/cask/cli/list_spec.rb b/Library/Homebrew/test/cask/cli/list_spec.rb
index fc1ffb5e2d..968afcca26 100644
--- a/Library/Homebrew/test/cask/cli/list_spec.rb
+++ b/Library/Homebrew/test/cask/cli/list_spec.rb
@@ -73,7 +73,7 @@ describe Hbc::CLI::List, :cask do
       casks.each(&InstallHelper.method(:install_without_artifacts_with_caskfile))
 
       transmission.artifacts.select { |a| a.is_a?(Hbc::Artifact::App) }.each do |artifact|
-        artifact.install_phase(command: Hbc::NeverSudoSystemCommand, force: false)
+        artifact.install_phase(command: NeverSudoSystemCommand, force: false)
       end
 
       expect {
diff --git a/Library/Homebrew/test/cask/cli/zap_spec.rb b/Library/Homebrew/test/cask/cli/zap_spec.rb
index e85120f5f7..308c832695 100644
--- a/Library/Homebrew/test/cask/cli/zap_spec.rb
+++ b/Library/Homebrew/test/cask/cli/zap_spec.rb
@@ -38,13 +38,13 @@ describe Hbc::CLI::Zap, :cask do
   #
   #   with_zap.must_be :installed?
   #
-  #   Hbc::FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application "System Events" to count processes whose bundle identifier is "my.fancy.package.app"'], '1')
-  #   Hbc::FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application id "my.fancy.package.app" to quit'])
-  #   Hbc::FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application "System Events" to count processes whose bundle identifier is "my.fancy.package.app.from.uninstall"'], '1')
-  #   Hbc::FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application id "my.fancy.package.app.from.uninstall" to quit'])
+  #   FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application "System Events" to count processes whose bundle identifier is "my.fancy.package.app"'], '1')
+  #   FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application id "my.fancy.package.app" to quit'])
+  #   FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application "System Events" to count processes whose bundle identifier is "my.fancy.package.app.from.uninstall"'], '1')
+  #   FakeSystemCommand.stubs_command(['/usr/bin/sudo', '-E', '--', '/usr/bin/osascript', '-e', 'tell application id "my.fancy.package.app.from.uninstall" to quit'])
   #
-  #   Hbc::FakeSystemCommand.expects_command(['/usr/bin/sudo', '-E', '--', with_zap.staged_path.join('MyFancyPkg','FancyUninstaller.tool'), '--please'])
-  #   Hbc::FakeSystemCommand.expects_command(['/usr/bin/sudo', '-E', '--', '/bin/rm', '-rf', '--',
+  #   FakeSystemCommand.expects_command(['/usr/bin/sudo', '-E', '--', with_zap.staged_path.join('MyFancyPkg','FancyUninstaller.tool'), '--please'])
+  #   FakeSystemCommand.expects_command(['/usr/bin/sudo', '-E', '--', '/bin/rm', '-rf', '--',
   #                                             Pathname.new('~/Library/Preferences/my.fancy.app.plist').expand_path])
   #
   #   Hbc::CLI::Zap.run('with-zap')
diff --git a/Library/Homebrew/test/cask/container/dmg_spec.rb b/Library/Homebrew/test/cask/container/dmg_spec.rb
index df99a6264a..a11d798ea7 100644
--- a/Library/Homebrew/test/cask/container/dmg_spec.rb
+++ b/Library/Homebrew/test/cask/container/dmg_spec.rb
@@ -6,7 +6,7 @@ describe Hbc::Container::Dmg, :cask do
       dmg = Hbc::Container::Dmg.new(
         transmission,
         Pathname(transmission.url.path),
-        Hbc::SystemCommand,
+        SystemCommand,
       )
 
       dmg.mount do |mounts|
diff --git a/Library/Homebrew/test/cask/container/naked_spec.rb b/Library/Homebrew/test/cask/container/naked_spec.rb
index f147b06b9d..4f3ec2e3d3 100644
--- a/Library/Homebrew/test/cask/container/naked_spec.rb
+++ b/Library/Homebrew/test/cask/container/naked_spec.rb
@@ -8,9 +8,9 @@ describe Hbc::Container::Naked, :cask do
     path                 = Pathname("/tmp/downloads/kevin-spacey.pkg")
     expected_destination = cask.staged_path.join("kevin spacey.pkg")
 
-    container = Hbc::Container::Naked.new(cask, path, Hbc::FakeSystemCommand)
+    container = Hbc::Container::Naked.new(cask, path, FakeSystemCommand)
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       ["/usr/bin/ditto", "--", path, expected_destination],
     )
 
diff --git a/Library/Homebrew/test/cask/download_strategy_spec.rb b/Library/Homebrew/test/cask/download_strategy_spec.rb
index 3a69edaaf4..0769bb0679 100644
--- a/Library/Homebrew/test/cask/download_strategy_spec.rb
+++ b/Library/Homebrew/test/cask/download_strategy_spec.rb
@@ -205,7 +205,7 @@ describe "download strategies", :cask do
 
   describe Hbc::SubversionDownloadStrategy do
     let(:url_options) { { using: :svn } }
-    let(:fake_system_command) { class_double(Hbc::SystemCommand) }
+    let(:fake_system_command) { class_double(SystemCommand) }
     let(:downloader) { Hbc::SubversionDownloadStrategy.new(cask, command: fake_system_command) }
 
     before do
diff --git a/Library/Homebrew/test/cask/dsl/postflight_spec.rb b/Library/Homebrew/test/cask/dsl/postflight_spec.rb
index 4ac3ae7cf7..a7877d1abf 100644
--- a/Library/Homebrew/test/cask/dsl/postflight_spec.rb
+++ b/Library/Homebrew/test/cask/dsl/postflight_spec.rb
@@ -3,7 +3,7 @@ require "test/support/helper/spec/shared_examples/hbc_staged"
 
 describe Hbc::DSL::Postflight, :cask do
   let(:cask) { Hbc::CaskLoader.load(cask_path("basic-cask")) }
-  let(:dsl) { Hbc::DSL::Postflight.new(cask, Hbc::FakeSystemCommand) }
+  let(:dsl) { Hbc::DSL::Postflight.new(cask, FakeSystemCommand) }
 
   it_behaves_like Hbc::DSL::Base
 
diff --git a/Library/Homebrew/test/cask/dsl/preflight_spec.rb b/Library/Homebrew/test/cask/dsl/preflight_spec.rb
index f78944c504..1d152e06ad 100644
--- a/Library/Homebrew/test/cask/dsl/preflight_spec.rb
+++ b/Library/Homebrew/test/cask/dsl/preflight_spec.rb
@@ -3,7 +3,7 @@ require "test/support/helper/spec/shared_examples/hbc_staged"
 
 describe Hbc::DSL::Preflight, :cask do
   let(:cask) { Hbc::CaskLoader.load(cask_path("basic-cask")) }
-  let(:dsl) { Hbc::DSL::Preflight.new(cask, Hbc::FakeSystemCommand) }
+  let(:dsl) { Hbc::DSL::Preflight.new(cask, FakeSystemCommand) }
 
   it_behaves_like Hbc::DSL::Base
 
diff --git a/Library/Homebrew/test/cask/dsl/uninstall_postflight_spec.rb b/Library/Homebrew/test/cask/dsl/uninstall_postflight_spec.rb
index b2af700dbd..189e526e29 100644
--- a/Library/Homebrew/test/cask/dsl/uninstall_postflight_spec.rb
+++ b/Library/Homebrew/test/cask/dsl/uninstall_postflight_spec.rb
@@ -2,7 +2,7 @@ require "test/support/helper/spec/shared_examples/hbc_dsl_base"
 
 describe Hbc::DSL::UninstallPostflight, :cask do
   let(:cask) { Hbc::CaskLoader.load(cask_path("basic-cask")) }
-  let(:dsl) { Hbc::DSL::UninstallPostflight.new(cask, Hbc::FakeSystemCommand) }
+  let(:dsl) { Hbc::DSL::UninstallPostflight.new(cask, FakeSystemCommand) }
 
   it_behaves_like Hbc::DSL::Base
 end
diff --git a/Library/Homebrew/test/cask/dsl/uninstall_preflight_spec.rb b/Library/Homebrew/test/cask/dsl/uninstall_preflight_spec.rb
index 8e7fa47eb4..8f4164b07d 100644
--- a/Library/Homebrew/test/cask/dsl/uninstall_preflight_spec.rb
+++ b/Library/Homebrew/test/cask/dsl/uninstall_preflight_spec.rb
@@ -3,7 +3,7 @@ require "test/support/helper/spec/shared_examples/hbc_staged"
 
 describe Hbc::DSL::UninstallPreflight, :cask do
   let(:cask) { Hbc::CaskLoader.load(cask_path("basic-cask")) }
-  let(:dsl) { Hbc::DSL::UninstallPreflight.new(cask, Hbc::FakeSystemCommand) }
+  let(:dsl) { Hbc::DSL::UninstallPreflight.new(cask, FakeSystemCommand) }
 
   it_behaves_like Hbc::DSL::Base
 
diff --git a/Library/Homebrew/test/cask/pkg_spec.rb b/Library/Homebrew/test/cask/pkg_spec.rb
index eda4f82ce1..2c1f38f0a7 100644
--- a/Library/Homebrew/test/cask/pkg_spec.rb
+++ b/Library/Homebrew/test/cask/pkg_spec.rb
@@ -1,6 +1,6 @@
 describe Hbc::Pkg, :cask do
   describe "#uninstall" do
-    let(:fake_system_command) { Hbc::NeverSudoSystemCommand }
+    let(:fake_system_command) { NeverSudoSystemCommand }
     let(:empty_response) { double(stdout: "", plist: { "volume" => "/", "install-location" => "", "paths" => {} }) }
     let(:pkg) { described_class.new("my.fake.pkg", fake_system_command) }
 
@@ -101,7 +101,7 @@ describe Hbc::Pkg, :cask do
   end
 
   describe "#info" do
-    let(:fake_system_command) { class_double(Hbc::SystemCommand) }
+    let(:fake_system_command) { class_double(SystemCommand) }
 
     let(:volume) { "/" }
     let(:install_location) { "tmp" }
@@ -148,7 +148,7 @@ describe Hbc::Pkg, :cask do
         "/usr/sbin/pkgutil",
         args: ["--pkg-info-plist", pkg_id],
       ).and_return(
-        Hbc::SystemCommand::Result.new(nil, pkg_info_plist, nil, 0),
+        SystemCommand::Result.new(nil, pkg_info_plist, nil, 0),
       )
 
       info = pkg.info
diff --git a/Library/Homebrew/test/support/helper/cask/fake_system_command.rb b/Library/Homebrew/test/support/helper/cask/fake_system_command.rb
index 4e7e53a956..b8f8aa4347 100644
--- a/Library/Homebrew/test/support/helper/cask/fake_system_command.rb
+++ b/Library/Homebrew/test/support/helper/cask/fake_system_command.rb
@@ -2,73 +2,71 @@ def sudo(*args)
   ["/usr/bin/sudo", "-E", "--"] + args.flatten
 end
 
-module Hbc
-  class FakeSystemCommand
-    def self.responses
-      @responses ||= {}
-    end
+class FakeSystemCommand
+  def self.responses
+    @responses ||= {}
+  end
 
-    def self.expectations
-      @expectations ||= {}
-    end
+  def self.expectations
+    @expectations ||= {}
+  end
 
-    def self.system_calls
-      @system_calls ||= Hash.new(0)
-    end
+  def self.system_calls
+    @system_calls ||= Hash.new(0)
+  end
 
-    def self.clear
-      @responses    = nil
-      @expectations = nil
-      @system_calls = nil
-    end
+  def self.clear
+    @responses    = nil
+    @expectations = nil
+    @system_calls = nil
+  end
 
-    def self.stubs_command(command, response = "")
-      command = command.map(&:to_s)
-      responses[command] = response
-    end
+  def self.stubs_command(command, response = "")
+    command = command.map(&:to_s)
+    responses[command] = response
+  end
 
-    def self.expects_command(command, response = "", times = 1)
-      command = command.map(&:to_s)
-      stubs_command(command, response)
-      expectations[command] = times
-    end
+  def self.expects_command(command, response = "", times = 1)
+    command = command.map(&:to_s)
+    stubs_command(command, response)
+    expectations[command] = times
+  end
 
-    def self.verify_expectations!
-      expectations.each do |command, times|
-        unless system_calls[command] == times
-          raise("expected #{command.inspect} to be run #{times} times, but got #{system_calls[command]}")
-        end
+  def self.verify_expectations!
+    expectations.each do |command, times|
+      unless system_calls[command] == times
+        raise("expected #{command.inspect} to be run #{times} times, but got #{system_calls[command]}")
       end
     end
+  end
 
-    def self.run(command_string, options = {})
-      command = Hbc::SystemCommand.new(command_string, options).command
-      puts command
-      unless responses.key?(command)
-        raise("no response faked for #{command.inspect}, faked responses are: #{responses.inspect}")
-      end
-      system_calls[command] += 1
-
-      response = responses[command]
-      if response.respond_to?(:call)
-        response.call(command_string, options)
-      else
-        Hbc::SystemCommand::Result.new(command, response, "", 0)
-      end
+  def self.run(command_string, options = {})
+    command = SystemCommand.new(command_string, options).command
+    puts command
+    unless responses.key?(command)
+      raise("no response faked for #{command.inspect}, faked responses are: #{responses.inspect}")
     end
+    system_calls[command] += 1
 
-    def self.run!(command, options = {})
-      run(command, options.merge(must_succeed: true))
+    response = responses[command]
+    if response.respond_to?(:call)
+      response.call(command_string, options)
+    else
+      SystemCommand::Result.new(command, response, "", 0)
     end
   end
+
+  def self.run!(command, options = {})
+    run(command, options.merge(must_succeed: true))
+  end
 end
 
 RSpec.configure do |config|
   config.after(:each) do
     begin
-      Hbc::FakeSystemCommand.verify_expectations!
+      FakeSystemCommand.verify_expectations!
     ensure
-      Hbc::FakeSystemCommand.clear
+      FakeSystemCommand.clear
     end
   end
 end
diff --git a/Library/Homebrew/test/support/helper/cask/never_sudo_system_command.rb b/Library/Homebrew/test/support/helper/cask/never_sudo_system_command.rb
index eb8b677f27..7842d4b178 100644
--- a/Library/Homebrew/test/support/helper/cask/never_sudo_system_command.rb
+++ b/Library/Homebrew/test/support/helper/cask/never_sudo_system_command.rb
@@ -1,9 +1,7 @@
-require "hbc/system_command"
+require "system_command"
 
-module Hbc
-  class NeverSudoSystemCommand < SystemCommand
-    def self.run(command, options = {})
-      super(command, options.merge(sudo: false))
-    end
+class NeverSudoSystemCommand < SystemCommand
+  def self.run(command, options = {})
+    super(command, options.merge(sudo: false))
   end
 end
diff --git a/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb b/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb
index b69c116fdb..1f2eb5b5d0 100644
--- a/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb
+++ b/Library/Homebrew/test/support/helper/spec/shared_examples/hbc_staged.rb
@@ -14,7 +14,7 @@ shared_examples Hbc::Staged do
   end
 
   it "can run system commands with list-form arguments" do
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       ["echo", "homebrew-cask", "rocks!"],
     )
 
@@ -28,7 +28,7 @@ shared_examples Hbc::Staged do
   it "can execute commands on the Info.plist file" do
     allow(staged).to receive(:bundle_identifier).and_return("com.example.BasicCask")
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       ["/usr/libexec/PlistBuddy", "-c", "Print CFBundleIdentifier", staged.info_plist_file],
     )
 
@@ -38,7 +38,7 @@ shared_examples Hbc::Staged do
   it "can set a key in the Info.plist file" do
     allow(staged).to receive(:bundle_identifier).and_return("com.example.BasicCask")
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       ["/usr/libexec/PlistBuddy", "-c", "Set :JVMOptions:JVMVersion 1.6+", staged.info_plist_file],
     )
 
@@ -49,7 +49,7 @@ shared_examples Hbc::Staged do
     fake_pathname = existing_path
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       ["/bin/chmod", "-R", "--", "777", fake_pathname],
     )
 
@@ -60,7 +60,7 @@ shared_examples Hbc::Staged do
     fake_pathname = existing_path
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       ["/bin/chmod", "-R", "--", "777", fake_pathname, fake_pathname],
     )
 
@@ -79,7 +79,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:current_user).and_return("fake_user")
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       sudo("/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname),
     )
 
@@ -92,7 +92,7 @@ shared_examples Hbc::Staged do
     allow(staged).to receive(:current_user).and_return("fake_user")
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       sudo("/usr/sbin/chown", "-R", "--", "fake_user:staff", fake_pathname, fake_pathname),
     )
 
@@ -104,7 +104,7 @@ shared_examples Hbc::Staged do
 
     allow(staged).to receive(:Pathname).and_return(fake_pathname)
 
-    Hbc::FakeSystemCommand.expects_command(
+    FakeSystemCommand.expects_command(
       sudo("/usr/sbin/chown", "-R", "--", "other_user:other_group", fake_pathname),
     )
 
diff --git a/Library/Homebrew/test/cask/system_command_result_spec.rb b/Library/Homebrew/test/system_command_result_spec.rb
similarity index 97%
rename from Library/Homebrew/test/cask/system_command_result_spec.rb
rename to Library/Homebrew/test/system_command_result_spec.rb
index 84d8b55fe8..fe2a8df80f 100644
--- a/Library/Homebrew/test/cask/system_command_result_spec.rb
+++ b/Library/Homebrew/test/system_command_result_spec.rb
@@ -1,6 +1,6 @@
-require "hbc/system_command"
+require "system_command"
 
-describe Hbc::SystemCommand::Result, :cask do
+describe SystemCommand::Result, :cask do
   describe "#plist" do
     subject { described_class.new(command, stdout, "", 0).plist }
 
diff --git a/Library/Homebrew/test/cask/system_command_spec.rb b/Library/Homebrew/test/system_command_spec.rb
similarity index 99%
rename from Library/Homebrew/test/cask/system_command_spec.rb
rename to Library/Homebrew/test/system_command_spec.rb
index eb6f8e0515..b1d732ac30 100644
--- a/Library/Homebrew/test/cask/system_command_spec.rb
+++ b/Library/Homebrew/test/system_command_spec.rb
@@ -1,4 +1,4 @@
-describe Hbc::SystemCommand, :cask do
+describe SystemCommand, :cask do
   describe "#initialize" do
     let(:env_args) { ["bash", "-c", 'printf "%s" "${A?}" "${B?}" "${C?}"'] }