Segfault that occasionally occurs upon completion of Minitest

segfault.log

Finished in 1832.41581s
25 tests, 1053 assertions, 0 failures, 2 errors, 1 skips
Writing XML reports to /cruisedata/jenkins-slave/workspace/SeleniumNewTests/selenium/rb/test/reports
I, [2013-07-10T08:31:27.387315 #24977]  INFO : Killing browser
/home/site/.rvm/gems/ruby-1.9.3-p385@rn_qa/gems/minitest-4.7.0/lib/minitest/unit.rb:775: [BUG] Segmentation fault
ruby 1.9.3p385 (2013-02-06 revision 39114) [x86_64-linux]

-- Control frame information -----------------------------------------------
c:0003 p:0028 s:0006 b:0006 l:0009f8 d:000005 BLOCK  /home/site/.rvm/gems/ruby-1.9.3-p385@rn_qa/gems/minitest-4.7.0/lib/minitest/unit.rb:775
c:0002 p:---- s:0004 b:0004 l:000003 d:000003 FINISH
c:0001 p:0000 s:0002 b:0002 l:002408 d:002408 TOP   

-- Ruby level backtrace information ----------------------------------------
/home/site/.rvm/gems/ruby-1.9.3-p385@rn_qa/gems/minitest-4.7.0/lib/minitest/unit.rb:775:in `block (2 levels) in autorun'

-- C level backtrace information -------------------------------------------
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x179efa) [0x7f8e87e83efa] vm_dump.c:796
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x5cde7) [0x7f8e87d66de7] error.c:258
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(rb_bug+0xb7) [0x7f8e87d67b37] error.c:277
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x10ec8f) [0x7f8e87e18c8f] signal.c:609
/lib64/libpthread.so.0() [0x356b40eee0]
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x166908) [0x7f8e87e70908] vm_method.c:370
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x16e973) [0x7f8e87e78973] vm_insnhelper.c:1375
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x16fba1) [0x7f8e87e79ba1] vm.c:1236
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x170b61) [0x7f8e87e7ab61] vm.c:686
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(rb_exec_end_proc+0x1cc) [0x7f8e87d6f09c] eval_jump.c:126
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(+0x6513a) [0x7f8e87d6f13a] eval.c:92
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(ruby_cleanup+0x132) [0x7f8e87d6f2b2] eval.c:133
/home/site/.rvm/rubies/ruby-1.9.3-p385/lib/libruby.so.1.9(ruby_run_node+0x25) [0x7f8e87d6f5f5] eval.c:244
/home/site/.rvm/rubies/ruby-1.9.3-p385/bin/ruby() [0x40081b] main.c:38
/lib64/libc.so.6(__libc_start_main+0xed) [0x356ac2135d]
/home/site/.rvm/rubies/ruby-1.9.3-p385/bin/ruby() [0x400849] main.c:40

-- Other runtime information -----------------------------------------------

* Loaded script: /home/site/.rvm/gems/ruby-1.9.3-p385@rn_qa/gems/rake-10.1.0/lib/rake/rake_test_loader.rb

test_helper.rb

  MiniTest::Unit.after_tests do
    if self.class_variable_defined? :@@browser and not @@browser.nil?
      LOG.info "Killing browser"
      @@browser.driver.quit
    end
    if self.class_variable_defined? :@@headless
      LOG.debug "Destroying Headless session"
      @@headless.destroy
    end
  end