diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc
index b6c7666e5..6448e87cc 100644
--- a/src/libstore/build/local-derivation-goal.cc
+++ b/src/libstore/build/local-derivation-goal.cc
@@ -1748,11 +1748,19 @@ void LocalDerivationGoal::runChild()
         if (drv->isBuiltin() && drv->builder == "builtin:fetchurl") {
            try {
                netrcData = readFile(settings.netrcFile);
+<<<<<<< HEAD
            } catch (SysError &) { }
 
            try {
                caFileData = readFile(settings.caFile);
            } catch (SysError &) { }
+=======
+           } catch (SystemError &) { }
+
+           try {
+               caFileData = readFile(settings.caFile);
+           } catch (SystemError &) { }
+>>>>>>> 9b818f14d (fix passing CA files into builtins:fetchurl sandbox)
         }
 
 #if __linux__
diff --git a/src/libstore/builtins/fetchurl.cc b/src/libstore/builtins/fetchurl.cc
index 7558ab494..b68b659d5 100644
--- a/src/libstore/builtins/fetchurl.cc
+++ b/src/libstore/builtins/fetchurl.cc
@@ -21,6 +21,16 @@ void builtinFetchurl(
 
     settings.caFile = "ca-certificates.crt";
     writeFile(settings.caFile, caFileData, 0600);
+<<<<<<< HEAD
+=======
+
+    auto out = get(drv.outputs, "out");
+    if (!out)
+        throw Error("'builtin:fetchurl' requires an 'out' output");
+
+    if (!(drv.type().isFixed() || drv.type().isImpure()))
+        throw Error("'builtin:fetchurl' must be a fixed-output or impure derivation");
+>>>>>>> 9b818f14d (fix passing CA files into builtins:fetchurl sandbox)
 
     auto getAttr = [&](const std::string & name) {
         auto i = drv.env.find(name);