Diff of `rspec-mocks` to remove circular dependency. Could be a problem if another rspec library calls into mocks then the line returned would be in the that library. This would be consistent with the behaviour that was here before `CleanCaller` was introduced though, and presumably if other libraries want to remove themselves from a trace that'…

gistfile1.diff

diff --git a/lib/rspec/mocks/clean_caller.rb b/lib/rspec/mocks/clean_caller.rb
index dc52c87..ed2a72d 100644
--- a/lib/rspec/mocks/clean_caller.rb
+++ b/lib/rspec/mocks/clean_caller.rb
@@ -6,21 +6,10 @@ module RSpec
     # the code using the library, which is far more useful than the particular
     # internal method that raised an error.
     class CleanCaller
-
-      # This list is an unfortunate dependency on other RSpec core libraries.
-      # It would be nice if this was not needed.
-      RSPEC_LIBS = %w[
-        core
-        mocks
-        expectations
-        matchers
-        rails
-      ]
+      LIB_DIR = File.dirname(File.expand_path('..', __FILE__))
 
       def self.first_non_rspec_line_in_caller
-        caller.find { |line|
-          line !~ %r{/lib/rspec/(#{RSPEC_LIBS.join('|')})(\.rb|/)}
-        }
+        caller.find { |line| !line.start_with?(LIB_DIR) }
       end
     end
   end