1 files changed, 27 insertions, 2 deletions

diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index e68edb38c..128c3c987 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -108,6 +108,31 @@ void Store::computeFSClosure(const StorePath & startPath,
 }
 
 
+std::optional<std::string> getDerivationCA(const BasicDerivation & drv)
+{
+    auto outputHashMode = drv.env.find("outputHashMode");
+    auto outputHash = drv.env.find("outputHash");
+
+    std::optional<HashType> ht = std::nullopt;
+    auto outputHashAlgo = drv.env.find("outputHashAlgo");
+    if (outputHashAlgo != drv.env.end())
+        ht = parseHashTypeOpt(outputHashAlgo->second);
+
+    if (outputHashMode != drv.env.end() && outputHash != drv.env.end()) {
+        auto h = Hash(outputHash->second, ht);
+        FileIngestionMethod ingestionMethod;
+        if (outputHashMode->second == "recursive")
+            ingestionMethod = FileIngestionMethod::Recursive;
+        else if (outputHashMode->second == "flat")
+            ingestionMethod = FileIngestionMethod::Flat;
+        else
+            throw Error("unknown ingestion method: '%s'", outputHashMode->second);
+        return makeFixedOutputCA(ingestionMethod, h);
+    }
+
+    return std::nullopt;
+}
+
 void Store::queryMissing(const std::vector<StorePathWithOutputs> & targets,
     StorePathSet & willBuild_, StorePathSet & willSubstitute_, StorePathSet & unknown_,
     unsigned long long & downloadSize_, unsigned long long & narSize_)
@@ -157,7 +182,7 @@ void Store::queryMissing(const std::vector<StorePathWithOutputs> & targets,
         auto outPath = parseStorePath(outPathS);
 
         SubstitutablePathInfos infos;
-        querySubstitutablePathInfos({outPath}, infos);
+        querySubstitutablePathInfos({{outPath, getDerivationCA(*drv)}}, infos);
 
         if (infos.empty()) {
             drvState_->lock()->done = true;
@@ -214,7 +239,7 @@ void Store::queryMissing(const std::vector<StorePathWithOutputs> & targets,
             if (isValidPath(path.path)) return;
 
             SubstitutablePathInfos infos;
-            querySubstitutablePathInfos({path.path}, infos);
+            querySubstitutablePathInfos({{path.path, std::nullopt}}, infos);
 
             if (infos.empty()) {
                 auto state(state_.lock());