refactor(tvix): Make Store::buildPaths return a Status r/1649

Make Store::buildPaths return a Status with [[nodiscard]] rather than
throwing exceptions to signal failure. This is the beginning of a long
road to refactor the entire store API to be status/statusor based
instead of using exceptions.

Change-Id: I2e32371c95a25b87ad129987c217d49c6d6e0c85
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1745
Tested-by: BuildkiteCI
Reviewed-by: kanepyork <rikingcoding@gmail.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/third_party/nix/src/libstore/remote-store.cc b/third_party/nix/src/libstore/remote-store.cc
index 41881f8ef9..6948d4e61d 100644
--- a/third_party/nix/src/libstore/remote-store.cc
+++ b/third_party/nix/src/libstore/remote-store.cc
@@ -3,6 +3,7 @@
 #include <cerrno>
 #include <cstring>
 
+#include <absl/status/status.h>
 #include <absl/strings/ascii.h>
 #include <fcntl.h>
 #include <glog/logging.h>
@@ -459,7 +460,8 @@ Path RemoteStore::addTextToStore(const std::string& name, const std::string& s,
   return readStorePath(*this, conn->from);
 }
 
-void RemoteStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
+absl::Status RemoteStore::buildPaths(const PathSet& drvPaths,
+                                     BuildMode buildMode) {
   auto conn(getConnection());
   conn->to << wopBuildPaths;
   if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 13) {
@@ -470,7 +472,8 @@ void RemoteStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
         /* Old daemons did not take a 'buildMode' parameter, so we
            need to validate it here on the client side.  */
         if (buildMode != bmNormal) {
-      throw Error(
+      return absl::Status(
+          absl::StatusCode::kInvalidArgument,
           "repairing or checking is not supported when building through the "
           "Nix daemon");
     }
@@ -485,6 +488,8 @@ void RemoteStore::buildPaths(const PathSet& drvPaths, BuildMode buildMode) {
   }
   conn.processStderr();
   readInt(conn->from);
+
+  return absl::OkStatus();
 }
 
 BuildResult RemoteStore::buildDerivation(const Path& drvPath,