enforced encoding="utf-8" for calls of fileinput.input, since it
may be necessary during the package build in some environments
Index: python-xmlschema/tests/test_package.py
===================================================================
--- python-xmlschema.orig/tests/test_package.py
+++ python-xmlschema/tests/test_package.py
@@ -42,7 +42,7 @@ class TestPackaging(unittest.TestCase):
         file_excluded = []
         files = glob.glob(os.path.join(self.source_dir, '*.py')) + \
             glob.glob(os.path.join(self.source_dir, 'validators/*.py'))
-        for line in fileinput.input(files):
+        for line in fileinput.input(files, encoding="utf-8"):
             if fileinput.isfirstline():
                 filename = fileinput.filename()
                 file_excluded = exclude.get(os.path.basename(filename), [])
@@ -66,7 +66,7 @@ class TestPackaging(unittest.TestCase):
                 os.path.join(self.package_dir, 'doc/conf.py'),
             ])
         version = filename = None
-        for line in fileinput.input(files):
+        for line in fileinput.input(files, encoding="utf-8"):
             if fileinput.isfirstline():
                 filename = fileinput.filename()
             lineno = fileinput.filelineno()
@@ -84,13 +84,13 @@ class TestPackaging(unittest.TestCase):
     def test_elementpath_requirement(self):
         package_dir = pathlib.Path(__file__).parent.parent
         ep_requirement = None
-        for line in fileinput.input(str(package_dir.joinpath('requirements-dev.txt'))):
+        for line in fileinput.input(str(package_dir.joinpath('requirements-dev.txt')), encoding="utf-8"):
             if 'elementpath' in line:
                 ep_requirement = line.strip()
 
         self.assertIsNotNone(ep_requirement, msg="Missing elementpath in requirements-dev.txt")
 
-        for line in fileinput.input(str(package_dir.joinpath('setup.py'))):
+        for line in fileinput.input(str(package_dir.joinpath('setup.py')), encoding="utf-8"):
             if 'elementpath' in line:
                 self.assertIn(ep_requirement, line, msg="Unmatched requirement in setup.py")