Fix completion generation for --repository

Library/Homebrew/cmd/--repository.rb

@@ -0,0 +1,33 @@
+# typed: strict
+# frozen_string_literal: true
+
+require "abstract_command"
+
+# This Ruby command exists to allow generation of completions for the Bash
+# version.
+# It is not meant to be run.
+module Homebrew
+  module Cmd
+    class Repository < AbstractCommand
+      sig { override.returns(String) }
+      def self.command_name = "--repository"
+
+      cmd_args do
+        description <<~EOS
+          Display where Homebrew's Git repository is located.
+
+          If <user>`/`<repo> are provided, display where tap <user>`/`<repo>'s directory is located.
+        EOS
+
+        named_args :tap
+
+        hide_from_man_page!
+      end
+
+      sig { override.void }
+      def run
+        raise StandardError, "This command is not meant to be run."
+      end
+    end
+  end
+end

Library/Homebrew/commands.rb

@@ -140,6 +140,7 @@ module Commands
   def self.find_internal_commands(path)
     find_commands(path).map(&:basename)
                        .map { basename_without_extension(_1) }
+                       .uniq
   end
 
   def self.external_commands