From fa6366a7dffa36209d82a7c75b5612ae887f824b Mon Sep 17 00:00:00 2001
From: Massimiliano Culpo <massimiliano.culpo@gmail.com>
Date: Thu, 16 Sep 2021 13:25:24 +0200
Subject: Add a deprecation warning when using the old concretizer (#25966)

---
 lib/spack/spack/spec.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index b026a3ab93..dba4924144 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -82,6 +82,7 @@ import operator
 import os
 import re
 import sys
+import warnings
 
 import ruamel.yaml as yaml
 import six
@@ -2399,6 +2400,13 @@ class Spec(object):
         """
         import spack.concretize
 
+        # Add a warning message to inform users that the original concretizer
+        # will be removed in v0.18.0
+        msg = ('the original concretizer is currently being used.\n\tUpgrade to '
+               '"clingo" at your earliest convenience. The original concretizer '
+               'will be removed from Spack starting at v0.18.0')
+        warnings.warn(msg)
+
         if not self.name:
             raise spack.error.SpecError(
                 "Attempting to concretize anonymous spec")
-- 
cgit v1.2.3-70-g09d2