1 files changed, 6 insertions, 1 deletions
diff --git a/src/libexpr/get-drvs.hh b/src/libexpr/get-drvs.hh
index 879dc8dbb45d..25d8baa559b2 100644
--- a/src/libexpr/get-drvs.hh
+++ b/src/libexpr/get-drvs.hh
@@ -31,6 +31,8 @@ private:
 
     bool metaInfoRead;
     MetaInfo meta;
+
+    bool failed; // set if we get an AssertionError
     
 public:
     string name;
@@ -40,7 +42,7 @@ public:
     /* !!! make this private */
     Bindings * attrs;
 
-    DrvInfo() : metaInfoRead(false), attrs(0) { };
+    DrvInfo() : metaInfoRead(false), failed(false), attrs(0) { };
 
     string queryDrvPath(EvalState & state) const;
     string queryOutPath(EvalState & state) const;
@@ -58,6 +60,9 @@ public:
     }
 
     void setMetaInfo(const MetaInfo & meta);
+
+    void setFailed() { failed = true; };
+    bool hasFailed() { return failed; };
 };