Avoid importing shutil for speed

Author: AA-Turner

sphinx/_cli/console_utilities.py

@@ -2,7 +2,6 @@
 
 import os
 import re
-import shutil
 import sys
 from typing import Dict, Pattern
 
@@ -24,7 +23,17 @@ def terminal_safe(s: str) -> str:
 
 def get_terminal_width() -> int:
     """Return the width of the terminal in columns."""
-    return shutil.get_terminal_size().columns - 1
+    try:
+        columns = int(os.environ.get('COLUMNS', 0))
+    except ValueError:
+        columns = 0
+    if columns > 1:
+        return columns - 1
+    try:
+        return os.get_terminal_size(sys.__stdout__.fileno()).columns - 1
+    except (AttributeError, ValueError, OSError):
+        # fallback
+        return 80 - 1
 
 
 _tw: int = get_terminal_width()