diff --git a/tests.py b/tests.py
index fcd9221..6f05d3f 100644
--- a/tests.py
+++ b/tests.py
@@ -2,6 +2,7 @@
 import locale
 import os
 import posixpath
+import re
 import shutil
 import subprocess
 import sys
@@ -928,12 +929,25 @@ class VCSHelper:
 
     # override in subclasses
     command = None  # type: Optional[str]
+    extra_env = {}
+
+    @property
+    def version(self):
+        if not hasattr(self, '_version'):
+            if not self.is_installed():
+                self._version = None
+        return self._version
+
+    @property
+    def version_tuple(self):
+        return tuple(map(int, re.findall(r'\d+', self.version)))
 
     def is_installed(self):
         try:
             p = subprocess.Popen([self.command, '--version'],
                                  stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
             stdout, stderr = p.communicate()
+            self._version = stdout.decode('ascii', 'backslashreplace').strip()
             rc = p.wait()
             return (rc == 0)
         except OSError:
@@ -946,14 +960,12 @@ def _run(self, *command):
             command = [s.encode(locale.getpreferredencoding()) for s in command]
         print('$', ' '.join(command))
         p = subprocess.Popen(command, stdout=subprocess.PIPE,
-                             stderr=subprocess.STDOUT)
+                             stderr=subprocess.STDOUT,
+                             env={**os.environ, **self.extra_env})
         stdout, stderr = p.communicate()
         rc = p.wait()
         if stdout:
-            print(
-                stdout if isinstance(stdout, str) else
-                stdout.decode('ascii', 'backslashreplace')
-            )
+            print(stdout.decode('ascii', 'backslashreplace'))
         if rc:
             raise subprocess.CalledProcessError(rc, command[0], output=stdout)
 
@@ -1051,9 +1063,15 @@ def test_get_vcs_files_empty(self):
 class GitHelper(VCSHelper):
 
     command = 'git'
+    extra_env = dict(
+        GIT_ALLOW_PROTOCOL='file',
+    )
 
     def _init_vcs(self):
-        self._run('git', 'init')
+        if self.version_tuple >= (2, 28):
+            self._run('git', 'init', '-b', 'main')
+        else:
+            self._run('git', 'init')
         self._run('git', 'config', 'user.name', 'Unit Test')
         self._run('git', 'config', 'user.email', 'test@example.com')