From 7d20da9a7b6a5b37ba0c2ba0c9a5bebf9492dc94 Mon Sep 17 00:00:00 2001
From: Milo Davis <davis.mil@husky.neu.edu>
Date: Wed, 1 Nov 2017 21:02:36 +0100
Subject: [PATCH] CLI: Show existing alias in error message

---
 src/client/client_aliases.ml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/client/client_aliases.ml b/src/client/client_aliases.ml
index 62921e2fa..635a80c5c 100644
--- a/src/client/client_aliases.ml
+++ b/src/client/client_aliases.ml
@@ -225,9 +225,13 @@ module Alias = functor (Entity : Entity) -> struct
                iter_s
                  (fun (n, _v) ->
                     if n = s then
+                      Entity.to_source cctxt _v >>=? fun value ->
                       failwith
-                        "the %s alias %s already exists, use -force true to update"
+                        "@[<v 2>The %s alias %s already exists.@,\
+                         The current value is %s.@,\
+                         Use -force true to update@]"
                         Entity.name n
+                        value
                     else
                       return ())
                  list