[compat] Suppress errors in enabling VT mode

Closes #1932

yt_dlp/YoutubeDL.py

@@ -3394,7 +3394,8 @@ def print_debug_header(self):
         def get_encoding(stream):
             ret = getattr(stream, 'encoding', 'missing (%s)' % type(stream).__name__)
             if not supports_terminal_sequences(stream):
-                ret += ' (No ANSI)'
+                from .compat import WINDOWS_VT_MODE
+                ret += ' (No VT)' if WINDOWS_VT_MODE is False else ' (No ANSI)'
             return ret
 
         encoding_str = 'Encodings: locale %s, fs %s, out %s, err %s, pref %s' % (

yt_dlp/compat.py

@@ -160,12 +160,20 @@ def compat_expanduser(path):
         compat_pycrypto_AES = None
 
 
+WINDOWS_VT_MODE = False if compat_os_name == 'nt' else None
+
+
 def windows_enable_vt_mode():  # TODO: Do this the proper way https://bugs.python.org/issue30075
     if compat_os_name != 'nt':
         return
+    global WINDOWS_VT_MODE
     startupinfo = subprocess.STARTUPINFO()
     startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
-    subprocess.Popen('', shell=True, startupinfo=startupinfo)
+    try:
+        subprocess.Popen('', shell=True, startupinfo=startupinfo)
+        WINDOWS_VT_MODE = True
+    except Exception:
+        pass
 
 
 #  Deprecated
@@ -226,6 +234,7 @@ def windows_enable_vt_mode():  # TODO: Do this the proper way https://bugs.pytho
 # Set public objects
 
 __all__ = [
+    'WINDOWS_VT_MODE',
     'compat_HTMLParseError',
     'compat_HTMLParser',
     'compat_HTTPError',

yt_dlp/utils.py

@@ -6592,7 +6592,8 @@ def jwt_decode_hs256(jwt):
 
 def supports_terminal_sequences(stream):
     if compat_os_name == 'nt':
-        if get_windows_version() < (10, 0, 10586):
+        from .compat import WINDOWS_VT_MODE  # Must be imported locally
+        if not WINDOWS_VT_MODE or get_windows_version() < (10, 0, 10586):
             return False
     elif not os.getenv('TERM'):
         return False