3 files changed, 15 insertions, 7 deletions

diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 20ed2de39..6e0a2b97b 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1072,7 +1072,7 @@ void DerivationGoal::haveDerivation()
     /* We are first going to try to create the invalid output paths
        through substitutes.  If that doesn't work, we'll build
        them. */
-    if (settings.useSubstitutes)
+    if (settings.useSubstitutes && !willBuildLocally(drv))
         foreach (PathSet::iterator, i, invalidOutputs)
             addWaitee(worker.makeSubstitutionGoal(*i, repair));
 
@@ -1273,6 +1273,12 @@ static bool canBuildLocally(const string & platform)
 }
 
 
+bool willBuildLocally(Derivation & drv)
+{
+    return drv.env["preferLocalBuild"] == "1" && canBuildLocally(drv.platform);
+}
+
+
 void DerivationGoal::tryToBuild()
 {
     trace("trying to build");
@@ -1337,11 +1343,10 @@ void DerivationGoal::tryToBuild()
 
     /* Don't do a remote build if the derivation has the attribute
        `preferLocalBuild' set. */
-    bool preferLocalBuild =
-        drv.env["preferLocalBuild"] == "1" && canBuildLocally(drv.platform);
+    bool buildLocally = willBuildLocally(drv);
 
     /* Is the build hook willing to accept this job? */
-    if (!preferLocalBuild) {
+    if (!buildLocally) {
         switch (tryBuildHook()) {
             case rpAccept:
                 /* Yes, it has started doing so.  Wait until we get
@@ -1364,7 +1369,7 @@ void DerivationGoal::tryToBuild()
        derivation prefers to be done locally, do it even if
        maxBuildJobs is 0. */
     unsigned int curBuilds = worker.getNrLocalBuilds();
-    if (curBuilds >= settings.maxBuildJobs && !(preferLocalBuild && curBuilds == 0)) {
+    if (curBuilds >= settings.maxBuildJobs && !(buildLocally && curBuilds == 0)) {
         worker.waitForBuildSlot(shared_from_this());
         outputLocks.unlock();
         return;
diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index 74ff26b9c..1bf3f9378 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -120,7 +120,8 @@ void queryMissing(StoreAPI & store, const PathSet & targets,
                 if (invalid.empty()) continue;
 
                 todoDrv.insert(*i);
-                if (settings.useSubstitutes) query.insert(invalid.begin(), invalid.end());
+                if (settings.useSubstitutes && !willBuildLocally(drv))
+                    query.insert(invalid.begin(), invalid.end());
             }
 
             else {
@@ -143,7 +144,7 @@ void queryMissing(StoreAPI & store, const PathSet & targets,
 
             PathSet outputs;
             bool mustBuild = false;
-            if (settings.useSubstitutes) {
+            if (settings.useSubstitutes && !willBuildLocally(drv)) {
                 foreach (DerivationOutputs::iterator, j, drv.outputs) {
                     if (!wantOutput(j->first, i2.second)) continue;
                     if (!store.isValidPath(j->second.path)) {
diff --git a/src/libstore/misc.hh b/src/libstore/misc.hh
index b4bd9ed8a..6f90ebe5e 100644
--- a/src/libstore/misc.hh
+++ b/src/libstore/misc.hh
@@ -32,5 +32,7 @@ void queryMissing(StoreAPI & store, const PathSet & targets,
     PathSet & willBuild, PathSet & willSubstitute, PathSet & unknown,
     unsigned long long & downloadSize, unsigned long long & narSize);
 
+bool willBuildLocally(Derivation & drv);
+
 
 }