feat(tvix): Thread a log sink through calls to buildDerivation r/1946

Similarly to how we did for buildPaths, add a std::ostream& log_sink
parameter to the build_derivation method on Store, and pass it std::cerr
when called at the top level by nix commands - most notably, the
build-remote hook binary, so that we get build logs when using tvix as a
remote builder.

Change-Id: I0f8f729ba8429d4838a0a135a5c2ac1e1a95d575
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2176
Tested-by: BuildkiteCI
Reviewed-by: andi <andi@notmuch.email>
Reviewed-by: kanepyork <rikingcoding@gmail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/third_party/nix/src/nix-daemon/nix-daemon-proto.cc b/third_party/nix/src/nix-daemon/nix-daemon-proto.cc
index 597ef2434a07..d6498e77c241 100644
--- a/third_party/nix/src/nix-daemon/nix-daemon-proto.cc
+++ b/third_party/nix/src/nix-daemon/nix-daemon-proto.cc
@@ -687,7 +687,10 @@ class WorkerServiceImpl final : public WorkerService::Service {
             return Status(grpc::StatusCode::INTERNAL, "Invalid build mode");
           }
 
-          BuildResult res = store_->buildDerivation(drv_path, drv, *build_mode);
+          BuildLogStreambuf log_buffer(writer);
+          std::ostream log_sink(&log_buffer);
+          BuildResult res =
+              store_->buildDerivation(log_sink, drv_path, drv, *build_mode);
 
           proto::BuildResult proto_res{};
           proto_res.set_status(res.status_to_proto());