GNU GCC `fails_with` are in the `fails_with :gcc => version` syntax. It's tracked separately from `fails_with :gcc`, so `fails_with :gcc` doesn't imply anything about GNU GCC versions and vice versa. It needs a few improvements before it's usable in your usecase, but soon you can do:

```ruby
fails_with :gcc => '4.3'
```

Or iterate over multiple versions by:

```ruby
%w[4.3 4.4 4.5].each do |v|
  fails_with :gcc => v
end
```