Running 'pip install --upgrade setuptools' with 'sudo' on macOS, fixing

#122

cibuildwheel/macos.py

@@ -86,7 +86,8 @@ def call(args, env=None, cwd=None, shell=False):
         # install pip & wheel
         call(['python', get_pip_script, '--no-setuptools', '--no-wheel'], env=env)
         call(['pip', '--version'], env=env)
-        call(['pip', 'install', '--upgrade', 'setuptools'], env=env)
+        # sudo required, because the removal of the old version of setuptools might cause problems with newer pip versions (see issue #122)
+        call(['sudo', 'pip', 'install', '--upgrade', 'setuptools'], env=env)
         call(['pip', 'install', 'wheel'], env=env)
         call(['pip', 'install', 'delocate'], env=env)
 
@@ -118,11 +119,11 @@ def call(args, env=None, cwd=None, shell=False):
         delocated_wheel = glob('/tmp/delocated_wheel/*.whl')[0]
 
         # install the wheel
-        call(['pip', 'install', delocated_wheel], env=env)
+        call(['pip', 'install', '--user', delocated_wheel], env=env)
 
         # test the wheel
         if test_requires:
-            call(['pip', 'install'] + test_requires, env=env)
+            call(['pip', 'install', '--user'] + test_requires, env=env)
         if test_command:
             # run the tests from $HOME, with an absolute path in the command
             # (this ensures that Python runs the tests against the installed wheel