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, 1 insertions, 1 deletions

diff --git a/third_party/nix/src/build-remote/build-remote.cc b/third_party/nix/src/build-remote/build-remote.cc
index 00bd833ac38e..43564a5eb74a 100644
--- a/third_party/nix/src/build-remote/build-remote.cc
+++ b/third_party/nix/src/build-remote/build-remote.cc
@@ -246,7 +246,7 @@ static int _main(int argc, char* argv[]) {
         readDerivation(store->realStoreDir + "/" + baseNameOf(drvPath)));
     drv.inputSrcs = inputs;
 
-    auto result = sshStore->buildDerivation(drvPath, drv);
+    auto result = sshStore->buildDerivation(std::cerr, drvPath, drv);
 
     if (!result.success()) {
       throw Error("build of '%s' on '%s' failed: %s", drvPath, storeUri,