This was an absolute nightmare to diagnose. It turns out there's a
kernel bug: poll with events = POLLHUP will receive an event for NOT
POLLHUP internally in the kernel, delete their event subscription, and
then not receive events for any HUP later. lol! lmao!!
We choose to use plain old EVFILT_READ because the watched fd can be
either a socket or a pipe and it's preferable to eat some spurious
wakeups than have separate paths for those. The alternative is using
EVFILT_SOCK, a private API that's existed for years and which netty
uses for its sockets, but that doesn't work on pipes.
Fixes: https://git.lix.systems/lix-project/lix/issues/729
Change-Id: If72b5d7a39f00320a9acccdbe81121cdb1a04c45
Well, I was trying to figure out
https://git.lix.systems/lix-project/lix/issues/729 in which this feature
is clearly just broken on macOS, but frustratingly, it seems that it
*does* work, except for the daemon. um........ sure.
Change-Id: Iaa962f045c16fdfa82854151c90a03e5cf0eea47
Jade Lovelace