
/run/rmilter is set by systemd, and have root:root ownership, which prevent pid file to write. This fix suggested to be promoted to 18.09 branch. (Although rmilter itself is deprecated, and I plan to remove it, after 18.09 would be released)
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.