Ruby

Damien Robert wrote:

The code is in https://github.com/DamienRobert/drain
You can run 'rake test' to (sometime, not often) get the core dump.

PS: I apologize that I was not able to get a minimal working example. I tried to do so in 'test_graph_segfault.rb' but it does not segfault. However removing test_graph.rb or test_converter.rb seems to prevent the segfault, but it is hard to tell because I am not able to get the segfault all the time. That's why I sent the coredump, I have several others (one where the message I get is an error due to a 'double free') if you need.

Some bugs are just like that - they exist somewhere out there but they are hard
to find or reproduce. Almost real heisenbugs. :)

nobu (Nobuyoshi Nakada) wrote:

Could you enable debugging?

So I think I have managed to bisect the segfault. When I comment a specific test I never see the segfault, but when I uncomment it I get (sometimes) the segfault. The test itself in isolation does not segfault, it is only when I run a fairly large amount of other tests that I can get the segfault. Contrary to what I was thinking at first, the tests about graphs with loops are not the ones responsible for the segfault. I can provide the debugging information if you still need but they only concern the other tests, not the one that causes the segfault.

Here is the tested code and the test:

 module Meta extend self #convert a class into a module using refinements #ex: (Class.new { include Meta.refined_module(String) { def length; super+5; end } }).new("foo").length #=> 8 #This uses the fact that a refining module of klass behaves as if it had #klass has his direct ancestor def refined_module(klass,&b) klass=klass.singleton_class unless Module===klass Module.new do #including the module rather than just returning it allow us to #still be able to use 'using' ('using' does not work directly on #refining modules, only the enclosing ones) include refine(klass) { module_eval(&b) if block_given? } end end end describe Meta do it "Can convert a class to module" do (Class.new { include DR::Meta.refined_module(String) { def length; super+5; end } }).new("foo").length.must_equal(8) end end