We'll be fixing the server so this won't trigger in practice,
but it demos the connection reuse problem.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Its semantics has changed slightly, this will let us use it to
drive batched logging in special circumstances.
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
In particular, the Dup2 syscall is not defined in the syscall
package on arm64, but is defined in x/sys/unix.
Signed-off-by: David Anderson <dave@natulte.net>
