1 files changed, 22 insertions, 8 deletions
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 1b5f41d4c4..5c082d90c8 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -1782,15 +1782,24 @@ class Spec(object):
 
     def concretize(self):
         """A spec is concrete if it describes one build of a package uniquely.
-           This will ensure that this spec is concrete.
+        This will ensure that this spec is concrete.
 
-           If this spec could describe more than one version, variant, or build
-           of a package, this will add constraints to make it concrete.
+        If this spec could describe more than one version, variant, or build
+        of a package, this will add constraints to make it concrete.
 
-           Some rigorous validation and checks are also performed on the spec.
-           Concretizing ensures that it is self-consistent and that it's
-           consistent with requirements of its pacakges.  See flatten() and
-           normalize() for more details on this.
+        Some rigorous validation and checks are also performed on the spec.
+        Concretizing ensures that it is self-consistent and that it's
+        consistent with requirements of its pacakges. See flatten() and
+        normalize() for more details on this.
+
+        It also ensures that:
+
+        .. code-block:: python
+
+            for x in self.traverse():
+                assert x.package.spec == x
+
+        which may not be true *during* the concretization step.
         """
         if not self.name:
             raise SpecError("Attempting to concretize anonymous spec")
@@ -1844,6 +1853,11 @@ class Spec(object):
         if matches:
             raise ConflictsInSpecError(self, matches)
 
+        # At this point the spec-package mutual references should
+        # be self-consistent
+        for x in self.traverse():
+            x.package.spec = x
+
     def _mark_concrete(self, value=True):
         """Mark this spec and its dependencies as concrete.
 
@@ -2463,7 +2477,7 @@ class Spec(object):
 
     def _dup(self, other, deps=True, cleardeps=True, caches=None):
         """Copy the spec other into self.  This is an overwriting
-        copy.  It does not copy any dependents (parents), but by default
+        copy. It does not copy any dependents (parents), but by default
         copies dependencies.
 
         To duplicate an entire DAG, call _dup() on the root of the DAG.