unittests: fix EncodingWarnings. minus 123 warnings collected by pytest

unittests/baseplatformtests.py

@@ -364,14 +364,14 @@ class BasePlatformTests(TestCase):
         if isinstance(args, str):
             args = [args]
         out = subprocess.check_output(self.mintro_command + args + [self.builddir],
-                                      universal_newlines=True)
+                                      encoding='utf-8', universal_newlines=True)
         return json.loads(out)
 
     def introspect_directory(self, directory, args):
         if isinstance(args, str):
             args = [args]
         out = subprocess.check_output(self.mintro_command + args + [directory],
-                                      universal_newlines=True)
+                                      encoding='utf-8', universal_newlines=True)
         try:
             obj = json.loads(out)
         except Exception as e:

unittests/helpers.py

@@ -167,7 +167,7 @@ def get_dynamic_section_entry(fname: str, entry: str) -> T.Optional[str]:
 
     try:
         raw_out = subprocess.check_output(['readelf', '-d', fname],
-                                          universal_newlines=True)
+                                          encoding='utf-8', universal_newlines=True)
     except FileNotFoundError:
         # FIXME: Try using depfixer.py:Elf() as a fallback
         raise unittest.SkipTest('readelf not found')

unittests/linuxliketests.py

@@ -1703,7 +1703,7 @@ class LinuxlikeTests(BasePlatformTests):
         p = subprocess.run([ar, 't', outlib],
                            stdout=subprocess.PIPE,
                            stderr=subprocess.DEVNULL,
-                           text=True, timeout=1)
+                           encoding='utf-8', text=True, timeout=1)
         obj_files = p.stdout.strip().split('\n')
         self.assertEqual(len(obj_files), 1)
         self.assertTrue(obj_files[0].endswith('-prelink.o'))

unittests/machinefiletests.py

@@ -50,7 +50,7 @@ def is_real_gnu_compiler(path):
     '''
     if not path:
         return False
-    out = subprocess.check_output([path, '--version'], universal_newlines=True, stderr=subprocess.STDOUT)
+    out = subprocess.check_output([path, '--version'], encoding='utf-8', universal_newlines=True, stderr=subprocess.STDOUT)
     return 'Free Software Foundation' in out
 
 cross_dir = Path(__file__).parent.parent / 'cross'

unittests/rewritetests.py

@@ -28,7 +28,7 @@ class RewriterTests(BasePlatformTests):
         if isinstance(args, str):
             args = [args]
         command = self.rewrite_command + ['--verbose', '--skip', '--sourcedir', directory] + args
-        p = subprocess.run(command, capture_output=True, text=True, timeout=60)
+        p = subprocess.run(command, capture_output=True, encoding='utf-8', text=True, timeout=60)
         print('STDOUT:')
         print(p.stdout)
         print('STDERR:')