1 files changed, 26 insertions, 0 deletions
diff --git a/lib/rubygems/commands/mirror_command.rb b/lib/rubygems/commands/mirror_command.rb
new file mode 100644
index 0000000000..b91a8db12d
--- /dev/null
+++ b/lib/rubygems/commands/mirror_command.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require_relative "../command"
+
+unless defined? Gem::Commands::MirrorCommand
+  class Gem::Commands::MirrorCommand < Gem::Command
+    def initialize
+      super("mirror", "Mirror all gem files (requires rubygems-mirror)")
+      begin
+        Gem::Specification.find_by_name("rubygems-mirror").activate
+      rescue Gem::LoadError
+        # no-op
+      end
+    end
+
+    def description # :nodoc:
+      <<-EOF
+The mirror command has been moved to the rubygems-mirror gem.
+      EOF
+    end
+
+    def execute
+      alert_error "Install the rubygems-mirror gem for the mirror command"
+    end
+  end
+end