(*os.File).Fd() implicitly sets file descriptor into blocking mode [1], [2]
We avoid that by calling (*os.File).SyscallConn instead.
This method was added in go1.12 (released on 2019-02-25)

[1]: https://pkg.go.dev/os#File.Fd
[2]: https://cs.opensource.google/go/go/+/refs/tags/go1.20.3:src/os/file_unix.go;l=80-87

This filename trick forces git to render previous commit diff
in a more comprehensible form

When compiled with go older than 1.12 creack/pty will not include a fix
for blocking Read() and will be prone to data races - but at least it will work

For more information see issues: #88 #114 #156 #162

Avoid calls to (*os.File).Fd() and operations on raw file descriptor ints