Add error context for most basic coercions

1 files changed, 8 insertions, 8 deletions

diff --git a/src/libexpr/get-drvs.cc b/src/libexpr/get-drvs.cc
index 7630c5ff4..975490d36 100644
--- a/src/libexpr/get-drvs.cc
+++ b/src/libexpr/get-drvs.cc
@@ -50,7 +50,7 @@ std::string DrvInfo::queryName() const
     if (name == "" && attrs) {
         auto i = attrs->find(state->sName);
         if (i == attrs->end()) throw TypeError("derivation name missing");
-        name = state->forceStringNoCtx(*i->value);
+        name = state->forceStringNoCtx(*i->value, noPos, "While evaluating the name of a DrvInfo");
     }
     return name;
 }
@@ -60,7 +60,7 @@ std::string DrvInfo::querySystem() const
 {
     if (system == "" && attrs) {
         auto i = attrs->find(state->sSystem);
-        system = i == attrs->end() ? "unknown" : state->forceStringNoCtx(*i->value, *i->pos);
+        system = i == attrs->end() ? "unknown" : state->forceStringNoCtx(*i->value, *i->pos, "While evaluating the system of a DrvInfo");
     }
     return system;
 }
@@ -108,15 +108,15 @@ DrvInfo::Outputs DrvInfo::queryOutputs(bool onlyOutputsToInstall)
         /* Get the ‘outputs’ list. */
         Bindings::iterator i;
         if (attrs && (i = attrs->find(state->sOutputs)) != attrs->end()) {
-            state->forceList(*i->value, *i->pos);
+            state->forceList(*i->value, *i->pos, "While evaluating the outputs of a DrvInfo");
 
             /* For each output... */
             for (auto elem : i->value->listItems()) {
                 /* Evaluate the corresponding set. */
-                std::string name(state->forceStringNoCtx(*elem, *i->pos));
+                std::string name(state->forceStringNoCtx(*elem, *i->pos, "While evaluating the name of one output of a DrvInfo"));
                 Bindings::iterator out = attrs->find(state->symbols.create(name));
                 if (out == attrs->end()) continue; // FIXME: throw error?
-                state->forceAttrs(*out->value, *i->pos);
+                state->forceAttrs(*out->value, *i->pos, "While evaluating the description of a DrvInfo output");
 
                 /* And evaluate its ‘outPath’ attribute. */
                 Bindings::iterator outPath = out->value->attrs->find(state->sOutPath);
@@ -151,7 +151,7 @@ std::string DrvInfo::queryOutputName() const
 {
     if (outputName == "" && attrs) {
         Bindings::iterator i = attrs->find(state->sOutputName);
-        outputName = i != attrs->end() ? state->forceStringNoCtx(*i->value) : "";
+        outputName = i != attrs->end() ? state->forceStringNoCtx(*i->value, noPos, "While evaluating the output name of a DrvInfo") : "";
     }
     return outputName;
 }
@@ -163,7 +163,7 @@ Bindings * DrvInfo::getMeta()
     if (!attrs) return 0;
     Bindings::iterator a = attrs->find(state->sMeta);
     if (a == attrs->end()) return 0;
-    state->forceAttrs(*a->value, *a->pos);
+    state->forceAttrs(*a->value, *a->pos, "While evaluating the `meta` attribute of a DrvInfo");
     meta = a->value->attrs;
     return meta;
 }
@@ -364,7 +364,7 @@ static void getDerivations(EvalState & state, Value & vIn,
                    `recurseForDerivations = true' attribute. */
                 if (i->value->type() == nAttrs) {
                     Bindings::iterator j = i->value->attrs->find(state.sRecurseForDerivations);
-                    if (j != i->value->attrs->end() && state.forceBool(*j->value, *j->pos))
+                    if (j != i->value->attrs->end() && state.forceBool(*j->value, *j->pos, "While evaluating the attribute `recurseForDerivations`"))
                         getDerivations(state, *i->value, pathPrefix2, autoArgs, drvs, done, ignoreAssertionFailures);
                 }
             }