Fix caller search

Until now it pointed to the place where dry-core or its dependants were
required. This is clearly a bug

lib/dry/core/deprecations.rb

@@ -25,6 +25,8 @@ module Core
     #
     # @api public
     module Deprecations
+      STACK = -> { caller.find { |l| l !~ %r{(lib/dry/core)|(gems)} } }
+
       class << self
         # Prints a warning
         #
@@ -45,8 +47,8 @@ def announce(name, msg, tag: nil)
         # @api private
         def deprecation_message(name, msg)
           <<-MSG
-            #{name} is deprecated and will be removed in the next major version
-            #{message(msg)}
+            #{ name } is deprecated and will be removed in the next major version
+            #{ msg }
           MSG
         end
 
@@ -62,14 +64,6 @@ def deprecated_method_message(old, new = nil, msg = nil)
           end
         end
 
-        # @api private
-        def message(msg)
-          <<-MSG
-            #{msg}
-            #{caller.detect { |l| l !~ %r{(lib/dry/core)|(gems)} }}
-          MSG
-        end
-
         # Returns the logger used for printing warnings.
         # You can provide your own with .set_logger!
         #
@@ -159,7 +153,7 @@ def deprecate(old_name, new_name = nil, message: nil)
             undef_method old_name if method_defined?(old_name)
 
             define_method(old_name) do |*args, &block|
-              mod.warn(full_msg)
+              mod.warn("#{ full_msg }\n#{ STACK.() }")
               __send__(new_name, *args, &block)
             end
           else
@@ -169,7 +163,7 @@ def deprecate(old_name, new_name = nil, message: nil)
             undef_method old_name
 
             define_method(old_name) do |*args, &block|
-              mod.warn(full_msg)
+              mod.warn("#{ full_msg }\n#{ STACK.() }")
               __send__(aliased_name, *args, &block)
             end
           end
@@ -193,7 +187,7 @@ def deprecate_class_method(old_name, new_name = nil, message: nil)
             undef_method old_name if method_defined?(old_name)
 
             define_method(old_name) do |*args, &block|
-              warn(full_msg)
+              warn("#{ full_msg }\n#{ STACK.() }")
               meth.call(*args, &block)
             end
           end