nix develop: do not assume that saved vars are set

This fixes NixOS#6809
jfly · Jul 15, 2022 · 04386f7 · 04386f7
1 parent de28796
commit 04386f7
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/nix/develop.cc b/src/nix/develop.cc
@@ -288,8 +288,10 @@ struct Common : InstallableCommand, MixProfile
 
         out << "unset shellHook\n";
 
-        for (auto & var : savedVars)
+        for (auto & var : savedVars) {
+            out << fmt("%s=${%s:-}\n", var, var);
             out << fmt("nix_saved_%s=\"$%s\"\n", var, var);
+        }
 
         buildEnvironment.toBash(out, ignoreVars);