This bug shouldn't be introduced, if I wrote clearer code last summer. Sorry :(. The _Executor is a little bit messy. The _M_match_queue is not cleared because it's treated `globally` between iterations (in _M_main_dispatch(..., __bfs)).
Add a new file general_testcases.cc; we can gradually move test cases to this single file to reduce duplicated compilation in testing? -- Regards, Tim Shen
