From 6801a423fc9abdfd2cb7307f2970553bcfad089d Mon Sep 17 00:00:00 2001
From: Ben Burdette <bburdette@gmail.com>
Date: Mon, 27 Dec 2021 16:28:45 -0700
Subject: [PATCH] :d env

---
 src/libcmd/repl.cc  | 26 +++++++++++++++-----------
 src/libexpr/eval.cc |  7 +++++--
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/src/libcmd/repl.cc b/src/libcmd/repl.cc
index 188bf75e4..3948ede02 100644
--- a/src/libcmd/repl.cc
+++ b/src/libcmd/repl.cc
@@ -402,7 +402,6 @@ StorePath NixRepl::getDerivationPath(Value & v) {
     return drvPath;
 }
 
-
 bool NixRepl::processLine(string line)
 {
     if (line == "") return true;
@@ -441,7 +440,8 @@ bool NixRepl::processLine(string line)
              << "  :doc <expr>    Show documentation of a builtin function\n"
              << "  :d <cmd>       Debug mode commands\n"
              << "  :d stack       Show call stack\n"
-             << "  :d stack <int> Detail for step N\n"
+             // << "  :d stack <int> Detail for stack level N\n"
+             << "  :d env         Show env stack\n"
              << "  :d error       Show current error\n";
     }
 
@@ -466,17 +466,21 @@ bool NixRepl::processLine(string line)
                       }
                   }
               }                   
-                 
-
+        } else if (arg == "env") {
+            std::cout << "env stack:" << std::endl;
+            auto iter = this->state->debugTraces.begin();
+            if (iter != this->state->debugTraces.end()) {
+               printStaticEnvBindings(iter->expr);
+            }                   
         }
         else if (arg == "error") {
-          if (this->debugError) {
-              showErrorInfo(std::cout, debugError->info(), true);
-          }
-          else
-          {
-              notice("error information not available");
-          }
+            if (this->debugError) {
+                showErrorInfo(std::cout, debugError->info(), true);
+            }
+            else
+            {
+                notice("error information not available");
+            }
         }
     }
 
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index d99e73471..f1e6cfdf2 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -691,10 +691,14 @@ std::optional<EvalState::Doc> EvalState::getDoc(Value & v)
 
 void printStaticEnvBindings(const StaticEnv &se, int lvl)
 {
+    std::cout << "Env level " << lvl << std::endl;
+  
     for (auto i = se.vars.begin(); i != se.vars.end(); ++i)
     {
-      std::cout << lvl << i->first << std::endl;
+      std::cout << i->first << " ";
     }
+    std::cout << std::endl;
+    std::cout << std::endl;
 
     if (se.up) {
       printStaticEnvBindings(*se.up, ++lvl);
@@ -730,7 +734,6 @@ void mapStaticEnvBindings(const StaticEnv &se, const Env &env, valmap & vm)
   }
 }
 
-
 valmap * mapStaticEnvBindings(const StaticEnv &se, const Env &env)
 {
     auto vm = new valmap();