test_openpty succeded on Gentoo, don't expect to fail it on this platform

Author: asvetlov

Lib/test/test_pty.py

@@ -5,6 +5,7 @@
 import_module('termios')
 
 import errno
+import pathlib
 import pty
 import os
 import sys
@@ -75,6 +76,14 @@ def _readline(fd):
 
 def expectedFailureIfStdinIsTTY(fun):
     # avoid isatty() for now
+    PLATFORM = platform.system()
+    if PLATFORM == "Linux":
+        os_release = pathlib.Path("/etc/os-release")
+        if os_release.exists():
+            # Actually the file has complex multi-line structure,
+            # these is no need to parse it for Gentoo check
+            if 'gentoo' in os_release.read_text().lower():
+                return fun
     try:
         tty.tcgetattr(pty.STDIN_FILENO)
         return unittest.expectedFailure(fun)