Use caller_locations again to find the right directory

Our switch to `const_source_location` seems to be unreliable with
Zeitwerk 2.6.0, and our `caller_locations` approach works — we just
have to inject the right frame when `inherited` is called.

This is the fix discussed in 1f6fe9c

Fixes #4

lib/conventional_extensions.rb

@@ -5,8 +5,8 @@
 module ConventionalExtensions
   Object.extend self # We're enriching object itself, so any object can call `load_extensions`.
 
-  def load_extensions(*extensions)
-    @loader = Loader.new(self, Object.const_source_location(name).first) unless loader_defined_before_entrance = defined?(@loader)
+  def load_extensions(*extensions, from: Frame.previous.path)
+    @loader = Loader.new(self, from) unless loader_defined_before_entrance = defined?(@loader)
     @loader.load(*extensions)
   ensure
     @loader = nil unless loader_defined_before_entrance
@@ -19,7 +19,13 @@ def self.load_on_inherited() = LoadOnInherited
   module LoadOnInherited
     def inherited(klass)
       super
-      klass.load_extensions
+      klass.load_extensions from: Frame.previous.path
+    end
+  end
+
+  module Frame
+    def self.previous
+      caller_locations(2, 1).first # Use 2 instead of 1 so we get the frame of who called us.
     end
   end
 

test/test_conventional_extensions.rb

@@ -11,7 +11,7 @@ def test_load_on_inherited_calls_load_extensions_when_inherited
     klass = Class.new do
       extend ConventionalExtensions.load_on_inherited
 
-      def self.load_extensions
+      def self.load_extensions(*)
         raise NotImplementedError
       end
     end