* Add a test for referring to another derivation's ‘drvPath’. This

currently fails in read-only mode.

tests/multiple-outputs.nix

@@ -32,6 +32,16 @@ rec {
       '';
   };
 
+  c = mkDerivation {
+    name = "multiple-outputs-c";
+    drv = b.drvPath;
+    builder = builtins.toFile "builder.sh"
+      ''
+        mkdir $out
+        ln -s $drv $out/drv
+      '';
+  };
+
   cyclic = (mkDerivation {
     name = "cyclic-outputs";
     outputs = [ "a" "b" ];

tests/multiple-outputs.sh

@@ -1,18 +1,36 @@
 source common.sh
 
-echo "Testing multiple outputs..."
+clearStore
 
+# Test whether read-only evaluation works when referring to the
+# ‘drvPath’ attribute.
+echo "evaluating c..."
+drvPath=$(nix-instantiate multiple-outputs.nix -A c --readonly-mode)
+
+# And check whether the resulting derivation explicitly depends on all
+# outputs.
+drvPath2=$(nix-instantiate multiple-outputs.nix -A c)
+[ "$drvPath" = "$drvPath2" ]
+grep -q 'multiple-outputs-a.drv",\["first","second"\]' $drvPath
+grep -q 'multiple-outputs-b.drv",\["out"\]' $drvPath
+
+# Do a build of something that depends on a derivation with multiple
+# outputs.
+echo "building b..."
 outPath=$(nix-build multiple-outputs.nix -A b)
 echo "output path is $outPath"
 [ "$(cat "$outPath"/file)" = "success" ]
 
 # Make sure that nix-build works on derivations with multiple outputs.
+echo "building a.first..."
 nix-build multiple-outputs.nix -A a.first
 
 # Cyclic outputs should be rejected.
+echo "building cyclic..."
 if nix-build multiple-outputs.nix -A cyclic; then
     echo "Cyclic outputs incorrectly accepted!"
     exit 1
 fi
 
+echo "collecting garbage..."
 nix-store --gc