test hangs with some versions of Socket

[chorny]

device.t hangs with Socket 2.016, does not hang after upgrade to 2.018.

[calid]

Isn't this more to do with the underlying libzmq than ZMQ::FFI? Seems like a bug that was subsequently fixed. Can't we just say only the latest update of any major version is supported and close this issue? Doesn't seem like there's anything that could be done at the binding level.

[calid]

@chorny I was wrong, this looks like a problem with the test code. I was able to reproduce this problem in both proxy.t and device.t. In some situations the TERM handler isn't executing and so the child doesn't exit. I'll need to dig into why exactly this is, but you can look here for a description of the problem and the workaround