1 files changed, 17 insertions, 13 deletions

diff --git a/src/nix/eval.cc b/src/nix/eval.cc
index 733b93661..ccee074e9 100644
--- a/src/nix/eval.cc
+++ b/src/nix/eval.cc
@@ -4,10 +4,11 @@
 #include "store-api.hh"
 #include "eval.hh"
 #include "eval-inline.hh"
-#include "json.hh"
 #include "value-to-json.hh"
 #include "progress-bar.hh"
 
+#include <nlohmann/json.hpp>
+
 using namespace nix;
 
 struct CmdEval : MixJSON, InstallableCommand
@@ -77,9 +78,9 @@ struct CmdEval : MixJSON, InstallableCommand
             if (pathExists(*writeTo))
                 throw Error("path '%s' already exists", *writeTo);
 
-            std::function<void(Value & v, const Pos & pos, const Path & path)> recurse;
+            std::function<void(Value & v, const PosIdx pos, const Path & path)> recurse;
 
-            recurse = [&](Value & v, const Pos & pos, const Path & path)
+            recurse = [&](Value & v, const PosIdx pos, const Path & path)
             {
                 state->forceValue(v, pos);
                 if (v.type() == nString)
@@ -88,18 +89,22 @@ struct CmdEval : MixJSON, InstallableCommand
                 else if (v.type() == nAttrs) {
                     if (mkdir(path.c_str(), 0777) == -1)
                         throw SysError("creating directory '%s'", path);
-                    for (auto & attr : *v.attrs)
+                    for (auto & attr : *v.attrs) {
+                        std::string_view name = state->symbols[attr.name];
                         try {
-                            if (attr.name == "." || attr.name == "..")
-                                throw Error("invalid file name '%s'", attr.name);
-                            recurse(*attr.value, *attr.pos, path + "/" + std::string(attr.name));
+                            if (name == "." || name == "..")
+                                throw Error("invalid file name '%s'", name);
+                            recurse(*attr.value, attr.pos, concatStrings(path, "/", name));
                         } catch (Error & e) {
-                            e.addTrace(*attr.pos, hintfmt("while evaluating the attribute '%s'", attr.name));
+                            e.addTrace(
+                                state->positions[attr.pos],
+                                hintfmt("while evaluating the attribute '%s'", name));
                             throw;
                         }
+                    }
                 }
                 else
-                    throw TypeError("value at '%s' is not a string or an attribute set", pos);
+                    throw TypeError("value at '%s' is not a string or an attribute set", state->positions[pos]);
             };
 
             recurse(*v, pos, *writeTo);
@@ -107,17 +112,16 @@ struct CmdEval : MixJSON, InstallableCommand
 
         else if (raw) {
             stopProgressBar();
-            std::cout << *state->coerceToString(noPos, *v, context);
+            std::cout << *state->coerceToString(noPos, *v, context, "while generating the eval command output");
         }
 
         else if (json) {
-            JSONPlaceholder jsonOut(std::cout);
-            printValueAsJSON(*state, true, *v, pos, jsonOut, context);
+            std::cout << printValueAsJSON(*state, true, *v, pos, context, false).dump() << std::endl;
         }
 
         else {
             state->forceValueDeep(*v);
-            logger->cout("%s", *v);
+            logger->cout("%s", printValue(*state, *v));
         }
     }
 };