Merge pull request #174618 from risicle/ris-coredns-darwin-fix

coredns: fix tests on darwin

pkgs/servers/dns/coredns/default.nix

···
-{ lib, buildGoModule, fetchFromGitHub }:
+{ lib
+, stdenv
+, buildGoModule
+, fetchFromGitHub
+}:
 
 buildGoModule rec {
   pname = "coredns";
···
 
     substituteInPlace test/readme_test.go \
       --replace "TestReadme" "SkipReadme"
+  '' + lib.optionalString stdenv.isDarwin ''
+    # loopback interface is lo0 on macos
+    sed -E -i 's/\blo\b/lo0/' plugin/bind/setup_test.go
   '';
 
   meta = with lib; {