2 files changed, 24 insertions, 2 deletions
diff --git a/src/libexpr/get-drvs.hh b/src/libexpr/get-drvs.hh
index 2d260c57beee..1e5d0a817cca 100644
--- a/src/libexpr/get-drvs.hh
+++ b/src/libexpr/get-drvs.hh
@@ -32,6 +32,8 @@ private:
 
     bool metaInfoRead;
     MetaInfo meta;
+
+    bool failed; // set if we get an AssertionError
     
 public:
     string name;
@@ -41,7 +43,7 @@ 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;
@@ -59,6 +61,9 @@ public:
     }
 
     void setMetaInfo(const MetaInfo & meta);
+
+    void setFailed() { failed = true; };
+    bool hasFailed() { return failed; };
 };
 
 
diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc
index 7aa6276e3a0a..2fd4246dd297 100644
--- a/src/nix-env/nix-env.cc
+++ b/src/nix-env/nix-env.cc
@@ -929,6 +929,21 @@ static void opQuery(Globals & globals,
             installed.insert(i->queryOutPath(globals.state));
     }
 
+
+    /* Query which paths have substitutes. */
+    SubstitutablePathInfos subs;
+    if (printStatus) {
+        PathSet paths;
+        foreach (vector<DrvInfo>::iterator, i, elems2)
+            try {
+                paths.insert(i->queryOutPath(globals.state));
+            } catch (AssertionError & e) {
+                printMsg(lvlTalkative, format("skipping derivation named `%1%' which gives an assertion failure") % i->name);
+                i->setFailed();
+            }
+        store->querySubstitutablePathInfos(paths, subs);
+    }
+
     
     /* Print the desired columns, or XML output. */
     Table table;
@@ -938,6 +953,8 @@ static void opQuery(Globals & globals,
     
     foreach (vector<DrvInfo>::iterator, i, elems2) {
         try {
+            if (i->hasFailed()) continue;
+            
             startNest(nest, lvlDebug, format("outputting query result `%1%'") % i->attrPath);
 
             if (globals.prebuiltOnly && !isPrebuilt(globals.state, *i)) continue;
@@ -949,7 +966,7 @@ static void opQuery(Globals & globals,
             XMLAttrs attrs;
 
             if (printStatus) {
-                bool hasSubs = store->hasSubstitutes(i->queryOutPath(globals.state));
+                bool hasSubs = subs.find(i->queryOutPath(globals.state)) != subs.end();
                 bool isInstalled = installed.find(i->queryOutPath(globals.state)) != installed.end();
                 bool isValid = store->isValidPath(i->queryOutPath(globals.state));
                 if (xmlOutput) {