Index: guix-1.4.0/nix/libstore/store-api.hh
===================================================================
--- guix-1.4.0.orig/nix/libstore/store-api.hh
+++ guix-1.4.0/nix/libstore/store-api.hh
@@ -4,6 +4,7 @@
 #include "serialise.hh"
 
 #include <string>
+#include <cstdint>
 #include <map>
 #include <memory>
 
Index: guix-1.4.0/nix/libstore/build.cc
===================================================================
--- guix-1.4.0.orig/nix/libstore/build.cc
+++ guix-1.4.0/nix/libstore/build.cc
@@ -91,7 +91,7 @@ typedef std::shared_ptr<Goal> GoalPtr;
 typedef std::weak_ptr<Goal> WeakGoalPtr;
 
 struct CompareGoalPtrs {
-    bool operator() (const GoalPtr & a, const GoalPtr & b);
+    bool operator() (const GoalPtr & a, const GoalPtr & b) const;
 };
 
 /* Set of goals. */
@@ -189,7 +189,7 @@ protected:
 };
 
 
-bool CompareGoalPtrs::operator() (const GoalPtr & a, const GoalPtr & b) {
+bool CompareGoalPtrs::operator() (const GoalPtr & a, const GoalPtr & b) const {
     string s1 = a->key();
     string s2 = b->key();
     return s1 < s2;