buildPaths(): Add an evalStore argument

With this, we don't have to copy the entire .drv closure to the
destination store ahead of time (or at all). Instead, buildPaths()
reads .drv files from the eval store and copies inputSrcs to the
destination store if it needs to build a derivation.

Issue #5025.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/libstore/build/worker.cc b/src/libstore/build/worker.cc
index 0f2ade348..a7a6b92a6 100644
--- a/src/libstore/build/worker.cc
+++ b/src/libstore/build/worker.cc
@@ -9,11 +9,12 @@
 
 namespace nix {
 
-Worker::Worker(Store & store)
+Worker::Worker(Store & store, Store & evalStore)
     : act(*logger, actRealise)
     , actDerivations(*logger, actBuilds)
     , actSubstitutions(*logger, actCopyPaths)
     , store(store)
+    , evalStore(evalStore)
 {
     /* Debugging: prevent recursive workers. */
     nrLocalBuilds = 0;