BinaryCacheStore: Implement getBuildLog()

We assume that build logs are stored under log/<drv>, e.g.

  /nix/store/q7ab198v13p0f8x8wgnd75dva7d5mip6-friday-devil-0.1.1.1.drv

maps to

  https://cache.nixos.org/log/q7ab198v13p0f8x8wgnd75dva7d5mip6-friday-devil-0.1.1.1.drv

1 files changed, 5 insertions, 1 deletions

diff --git a/src/libstore/local-fs-store.cc b/src/libstore/local-fs-store.cc
index c5da73dba3..002ee4a65c 100644
--- a/src/libstore/local-fs-store.cc
+++ b/src/libstore/local-fs-store.cc
@@ -95,7 +95,11 @@ std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path & path_)
     assertStorePath(path);
 
     if (!isDerivation(path)) {
-        path = queryPathInfo(path)->deriver;
+        try {
+            path = queryPathInfo(path)->deriver;
+        } catch (InvalidPath &) {
+            return nullptr;
+        }
         if (path == "") return nullptr;
     }