Miss Dada  🏳️‍⚧️

What happens when you run this code? ``` require 'pathname' require 'tempfile' def make_pathname(value = http://Tempfile.new ("log")) http://Pathname.new (value) end p = make_pathname FileUtils.touch(p) puts "File: #{p.file?}" GC.start puts "File: #{p.file?}" ```

If you said a "GC bug in Ruby" then I think you're right: ``` $ ruby scratch.rb File: true File: false ```

Tempfile is implemented as an object that deletes itself when it's finalizer is run: https://github.com/ruby/ruby/blob/935d0b3d05dfc8b30bba505792129bf0e33ebe3b/lib/tempfile.rb#L132 …

Pathname is implemented in C and it appears does not keep a reference to the original argument. So in this case, the only thing keeping the Tempfile "alive" is the reference to Pathname, which doesn't exist. So when GC is run, it thinks nothing references the Tempfile