nixos/httpd: symlink apache configuration to /etc/httpd/httpd.conf for use in the apachectl command

nixos/modules/services/web-servers/apache-httpd/default.nix

@@ -629,6 +629,9 @@ in
 
     environment.systemPackages = [httpd];
 
+    # required for "apachectl configtest"
+    environment.etc."httpd/httpd.conf".source = httpdConf;
+
     services.httpd.phpOptions =
       ''
         ; Needed for PHP's mail() function.

pkgs/servers/http/apache-httpd/2.4.nix

@@ -39,6 +39,7 @@ stdenv.mkDerivation rec {
   prePatch = ''
     sed -i config.layout -e "s|installbuilddir:.*|installbuilddir: $dev/share/build|"
     sed -i support/apachectl.in -e 's|@LYNX_PATH@|${lynx}/bin/lynx|'
+    sed -i support/apachectl.in -e 's|$HTTPD -t|$HTTPD -t -f /etc/httpd/httpd.conf|'
   '';
 
   # Required for ‘pthread_cancel’.