Fix tests that use relative imports.

src/gevent/testing/testrunner.py

@@ -415,12 +415,7 @@ def _setup_environ(debug=False):
         # Python 3.6
         os.environ['PYTHONMALLOC'] = 'debug'
 
-    if (sys.version_info == (3, 7, 0, 'beta', 2)
-            and (os.environ.get("PYTHONDEVMODE") or os.environ.get('PYTHONMALLOC'))):
-        # See https://twitter.com/ossmkitty/status/970693025130311680
-        # https://bugs.python.org/issue33005
-        os.environ.pop('PYTHONDEVMODE', None)
-        os.environ.pop('PYTHONMALLOC', None)
+
 
 def main():
     import argparse
@@ -485,6 +480,10 @@ def main():
             # XXX: Add a way to force these.
             print("Not running tests on pypy with c-ares; not a supported configuration")
             return
+        if options.package:
+            # Put this directory on the path so relative imports work.
+            package_dir = _dir_from_package_name(options.package)
+            os.environ['PYTHONPATH'] = os.environ.get('PYTHONPATH', "") + os.pathsep + package_dir
         run_many(tests, configured_failing_tests=FAILING_TESTS, failfast=options.failfast, quiet=options.quiet)
 
 

src/gevent/tests/test__environ.py

@@ -6,7 +6,7 @@ import subprocess
 
 if sys.argv[1:] == []:
     os.environ['GEVENT_BACKEND'] = 'select'
-    popen = subprocess.Popen([sys.executable, 'test__environ.py', '1'])
+    popen = subprocess.Popen([sys.executable, __file__, '1'])
     assert popen.wait() == 0, popen.poll()
 else:
     hub = gevent.get_hub()

src/gevent/tests/test__monkey_scope.py

@@ -10,6 +10,13 @@ from subprocess import PIPE
 class TestRun(unittest.TestCase):
     maxDiff = None
 
+    def setUp(self):
+        self.cwd = os.getcwd()
+        os.chdir(os.path.dirname(__file__))
+
+    def tearDown(self):
+        os.chdir(self.cwd)
+
     def _run(self, script):
         env = os.environ.copy()
         env['PYTHONWARNINGS'] = 'ignore'