Motivation for this change

grc needs a config file - by default that is /etc/grc.conf but we patch that to /nix/store/....grc/etc. The problem is that we cannot then provide custom config in /etc/grc.conf, so instead patch the /usr/local/etc/grc.conf location to point to the store and leave /etc/grc.conf alone.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Notify maintainers

cc @lovek323 @AndersonTorres