Problem: create_ipc_wildcard_address can fail #4732
Merged
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check and handle failure as a fallback to tcp
I believe this is the cause of #4730
There may be a better underlying fix to prevent the failure in the first place, but this treats failure to create the path for the ipc socket as a condition for falling back on tcp, just like failing to create the AF_UNIX socket itself, rather than ignoring the error and assuming success, which may fail later in epoll with EBADF.
I haven't been able to explain why this failure occurs in very peculiar scenarios (see #4730 and various linked issues through pyzmq), but this patch causes at least one of those cases to succeed, if I've done my tests correctly. Setting
$env:TMP
to a nonexistent or non-writable directory seems to provoke it sometimes as well.