fix(3p/nix/libexpr): Actually use AttributeMap type alias r/827

Without this alias, the garbage-collecting allocator won't be used and
allocated attribute set values won't be visible during GC.

1 files changed, 2 insertions, 2 deletions

diff --git a/third_party/nix/src/libexpr/attr-set.hh b/third_party/nix/src/libexpr/attr-set.hh
index cdfe9e41d5..19d1c8f530 100644
--- a/third_party/nix/src/libexpr/attr-set.hh
+++ b/third_party/nix/src/libexpr/attr-set.hh
@@ -38,7 +38,7 @@ using AttributeMap =
 
 class Bindings {
  public:
-  typedef absl::btree_map<Symbol, Attr>::iterator iterator;
+  typedef AttributeMap::iterator iterator;
 
   // Allocate a new attribute set that is visible to the garbage
   // collector.
@@ -79,7 +79,7 @@ class Bindings {
   friend class EvalState;
 
  private:
-  absl::btree_map<Symbol, Attr> attributes_;
+  AttributeMap attributes_;
 };
 
 }  // namespace nix