diff -up Declare-Constraints-Simple-0.03/Makefile.PL.orig Declare-Constraints-Simple-0.03/Makefile.PL
--- Declare-Constraints-Simple-0.03/Makefile.PL.orig	2017-05-16 15:25:25.495090362 +0200
+++ Declare-Constraints-Simple-0.03/Makefile.PL	2017-05-16 15:25:39.848030454 +0200
@@ -1,3 +1,4 @@
+BEGIN { push @INC, '.'; }
 use inc::Module::Install;
 use warnings;
 use strict;