Disable SA_RESTART for some signals on macOS
Disable SA_RESTART for some signals on macOS

Disables the SA_RESTART behavior on macOS which causes:

> Restarting of pending calls is requested by setting the SA_RESTART bit
> in sa_flags. The affected system calls include read(2), write(2),
> sendto(2), recvfrom(2), sendmsg(2) and recvmsg(2) on a communications
> channel or a slow device (such as a terminal, but not a regular file)
> and during a wait(2) or ioctl(2).

From: https://man.openbsd.org/sigaction#SA_RESTART

This being set on macOS caused a bug where read() calls to the daemon
socket were blocking after a SIGINT was received. As a result,
checkInterrupt was never reached even though the signal was received
by the signal handler thread.

On Linux, SA_RESTART is disabled by default. This probably effects
other BSDs but I don’t have the ability to test it there right now.

NixOS/nix,NixOS/nix,NixOS/nix,NixOS/nix,NixOS/nix