feat(tvix): Write build logs into the build log sink r/1697

This *should* wire up the builder's logs all the way back through the
gRPC client, where they are then conveniently discarded.

Change-Id: I65f22526d0b5a8b8d90f28665bc1b4bc7f7c802a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1825
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI

1 files changed, 4 insertions, 3 deletions

diff --git a/third_party/nix/src/libstore/build.cc b/third_party/nix/src/libstore/build.cc
index bdcb7a69f4dc..60890732e965 100644
--- a/third_party/nix/src/libstore/build.cc
+++ b/third_party/nix/src/libstore/build.cc
@@ -1473,7 +1473,7 @@ void DerivationGoal::tryToBuild() {
     if (hook) {
       msg += fmt(" on '%s'", machineName);
     }
-    LOG(INFO) << msg << "[" << drvPath << "]";
+    log_sink_ << msg << "[" << drvPath << "]";
     mcRunningBuilds =
         std::make_unique<MaintainCount<uint64_t>>(worker.runningBuilds);
   };
@@ -3782,6 +3782,7 @@ void DerivationGoal::deleteTmpDir(bool force) {
   }
 }
 
+// TODO(tazjin): What ... what does this function ... do?
 void DerivationGoal::handleChildOutput(int fd, const std::string& data) {
   if ((hook && fd == hook->builderOut.readSide.get()) ||
       (!hook && fd == builderOut.readSide.get())) {
@@ -3824,7 +3825,7 @@ void DerivationGoal::handleChildOutput(int fd, const std::string& data) {
   }
 }
 
-void DerivationGoal::handleEOF(int fd) {
+void DerivationGoal::handleEOF(int /* fd */) {
   if (!currentLogLine.empty()) {
     flushLine();
   }
@@ -3834,7 +3835,7 @@ void DerivationGoal::handleEOF(int fd) {
 void DerivationGoal::flushLine() {
   if (settings.verboseBuild &&
       (settings.printRepeatedBuilds || curRound == 1)) {
-    LOG(INFO) << currentLogLine;
+    log_sink_ << currentLogLine;
   } else {
     logTail.push_back(currentLogLine);
     if (logTail.size() > settings.logLines) {