Fix: mkdir might also raise Errno::EROFS

Author: kares

lib/rubygems.rb

@@ -469,7 +469,7 @@ def self.ensure_subdirectories(dir, mode, subdirs) # :nodoc:
       next if File.exist? subdir
       begin
         FileUtils.mkdir_p subdir, **options
-      rescue Errno::EACCES, Errno::ENOTDIR
+      rescue SystemCallError
       end
     end
   ensure