···228 '';
229 };
230 protocol = mkOption {
231- type = types.enum [ "ssh" "ssh-ng" ];
232 default = "ssh";
233 example = "ssh-ng";
234 description = lib.mdDoc ''
235 The protocol used for communicating with the build machine.
236 Use `ssh-ng` if your remote builder and your
237 local Nix version support that improved protocol.
000238 '';
239 };
240 system = mkOption {
···680 concatMapStrings
681 (machine:
682 (concatStringsSep " " ([
683- "${machine.protocol}://${optionalString (machine.sshUser != null) "${machine.sshUser}@"}${machine.hostName}"
684 (if machine.system != null then machine.system else if machine.systems != [ ] then concatStringsSep "," machine.systems else "-")
685 (if machine.sshKey != null then machine.sshKey else "-")
686 (toString machine.maxJobs)
···228 '';
229 };
230 protocol = mkOption {
231+ type = types.enum [ null "ssh" "ssh-ng" ];
232 default = "ssh";
233 example = "ssh-ng";
234 description = lib.mdDoc ''
235 The protocol used for communicating with the build machine.
236 Use `ssh-ng` if your remote builder and your
237 local Nix version support that improved protocol.
238+239+ Use `null` when trying to change the special localhost builder
240+ without a protocol which is for example used by hydra.
241 '';
242 };
243 system = mkOption {
···683 concatMapStrings
684 (machine:
685 (concatStringsSep " " ([
686+ "${optionalString (machine.protocol != null) "${machine.protocol}://"}${optionalString (machine.sshUser != null) "${machine.sshUser}@"}${machine.hostName}"
687 (if machine.system != null then machine.system else if machine.systems != [ ] then concatStringsSep "," machine.systems else "-")
688 (if machine.sshKey != null then machine.sshKey else "-")
689 (toString machine.maxJobs)