--- a/setup.py
+++ b/setup.py
@@ -487,16 +487,9 @@ class PyBuildExt(build_ext):
             return ['m']
 
     def detect_modules(self):
-        # Ensure that /usr/local is always used, but the local build
-        # directories (i.e. '.' and 'Include') must be first.  See issue
-        # 10520.
-        if not cross_compiling:
-            add_dir_to_list(self.compiler.library_dirs, '/usr/local/lib')
-            add_dir_to_list(self.compiler.include_dirs, '/usr/local/include')
         # only change this for cross builds for 3.3, issues on Mageia
         if cross_compiling:
             self.add_gcc_paths()
-        self.add_multiarch_paths()
 
         # Add paths specified in the environment variables LDFLAGS and
         # CPPFLAGS for header and library files.