/dev/net/tun not pollable

[crioto]

In version 1.12 of Go a Sysconn was introduced to os.File for ioctl calls, that is used for setting up device. Currently p2p doesn't support polling and during the process of instance creation we're getting error: /dev/net/tun: not pollable which happens during first attempt to read data from TAP interface. Afterwards, instance destroys itself, but start command exits with exit code 0, because interface creation went without any problems. We need to modify current code of tap interfaces on Linux to support latest versions of Go.

[akarasulu]

The logic is confusing me can you clarify?

Currently p2p doesn't support polling and during the process of instance creation we're getting error: /dev/net/tun: not pollable

My confusion: Why would we get the error if p2p is not attempting a poll operation on the device?

[crioto]

We create interface (file descriptor) and epoll initializes it with poll flags and then read operation fails, because tun interface is not pollable.